Data Cleaning & Manipulation

Monday, April 17

Today we will…

Review PA 2: Using Data Visualization to Find the Penguins
Look at our Ugly Graphics of Penguins!
Review Lab 2
New Material
- Using dplyr verbs to manipulate data
PA 3: Identify the Mystery College

Example Data set – Cereal

library(liver)
data(cereal)

Data Structure
Data Head
Data Summary

str(cereal, give.attr = FALSE)

'data.frame':   77 obs. of  16 variables:
 $ name    : Factor w/ 77 levels "100% Bran","100% Natural Bran",..: 1 2 3 4 5 6 7 8 9 10 ...
 $ manuf   : Factor w/ 7 levels "A","G","K","N",..: 4 6 3 3 7 2 3 2 7 5 ...
 $ type    : Factor w/ 2 levels "cold","hot": 1 1 1 1 1 1 1 1 1 1 ...
 $ calories: int  70 120 70 50 110 110 110 130 90 90 ...
 $ protein : int  4 3 4 4 2 2 2 3 2 3 ...
 $ fat     : int  1 5 1 0 2 2 0 2 1 0 ...
 $ sodium  : int  130 15 260 140 200 180 125 210 200 210 ...
 $ fiber   : num  10 2 9 14 1 1.5 1 2 4 5 ...
 $ carbo   : num  5 8 7 8 14 10.5 11 18 15 13 ...
 $ sugars  : int  6 8 5 0 8 10 14 8 6 5 ...
 $ potass  : int  280 135 320 330 -1 70 30 100 125 190 ...
 $ vitamins: int  25 0 25 25 25 25 25 25 25 25 ...
 $ shelf   : int  3 3 3 3 3 1 2 3 1 3 ...
 $ weight  : num  1 1 1 1 1 1 1 1.33 1 1 ...
 $ cups    : num  0.33 1 0.33 0.5 0.75 0.75 1 0.75 0.67 0.67 ...
 $ rating  : num  68.4 34 59.4 93.7 34.4 ...

head(cereal)

                       name manuf type calories protein fat sodium fiber carbo
1                 100% Bran     N cold       70       4   1    130  10.0   5.0
2         100% Natural Bran     Q cold      120       3   5     15   2.0   8.0
3                  All-Bran     K cold       70       4   1    260   9.0   7.0
4 All-Bran with Extra Fiber     K cold       50       4   0    140  14.0   8.0
5            Almond Delight     R cold      110       2   2    200   1.0  14.0
6   Apple Cinnamon Cheerios     G cold      110       2   2    180   1.5  10.5
  sugars potass vitamins shelf weight cups   rating
1      6    280       25     3      1 0.33 68.40297
2      8    135        0     3      1 1.00 33.98368
3      5    320       25     3      1 0.33 59.42551
4      0    330       25     3      1 0.50 93.70491
5      8     -1       25     3      1 0.75 34.38484
6     10     70       25     1      1 0.75 29.50954

summary(cereal)

                        name    manuf    type       calories    
 100% Bran                : 1   A: 1   cold:74   Min.   : 50.0  
 100% Natural Bran        : 1   G:22   hot : 3   1st Qu.:100.0  
 All-Bran                 : 1   K:23             Median :110.0  
 All-Bran with Extra Fiber: 1   N: 6             Mean   :106.9  
 Almond Delight           : 1   P: 9             3rd Qu.:110.0  
 Apple Cinnamon Cheerios  : 1   Q: 8             Max.   :160.0  
 (Other)                  :71   R: 8                            
    protein           fat            sodium          fiber       
 Min.   :1.000   Min.   :0.000   Min.   :  0.0   Min.   : 0.000  
 1st Qu.:2.000   1st Qu.:0.000   1st Qu.:130.0   1st Qu.: 1.000  
 Median :3.000   Median :1.000   Median :180.0   Median : 2.000  
 Mean   :2.545   Mean   :1.013   Mean   :159.7   Mean   : 2.152  
 3rd Qu.:3.000   3rd Qu.:2.000   3rd Qu.:210.0   3rd Qu.: 3.000  
 Max.   :6.000   Max.   :5.000   Max.   :320.0   Max.   :14.000  
                                                                 
     carbo          sugars           potass          vitamins     
 Min.   :-1.0   Min.   :-1.000   Min.   : -1.00   Min.   :  0.00  
 1st Qu.:12.0   1st Qu.: 3.000   1st Qu.: 40.00   1st Qu.: 25.00  
 Median :14.0   Median : 7.000   Median : 90.00   Median : 25.00  
 Mean   :14.6   Mean   : 6.922   Mean   : 96.08   Mean   : 28.25  
 3rd Qu.:17.0   3rd Qu.:11.000   3rd Qu.:120.00   3rd Qu.: 25.00  
 Max.   :23.0   Max.   :15.000   Max.   :330.00   Max.   :100.00  
                                                                  
     shelf           weight          cups           rating     
 Min.   :1.000   Min.   :0.50   Min.   :0.250   Min.   :18.04  
 1st Qu.:1.000   1st Qu.:1.00   1st Qu.:0.670   1st Qu.:33.17  
 Median :2.000   Median :1.00   Median :0.750   Median :40.40  
 Mean   :2.208   Mean   :1.03   Mean   :0.821   Mean   :42.67  
 3rd Qu.:3.000   3rd Qu.:1.00   3rd Qu.:1.000   3rd Qu.:50.83  
 Max.   :3.000   Max.   :1.50   Max.   :1.500   Max.   :93.70

Data Wrangling with `dplyr`

`dplyr`

dplyr provides us with the “Grammar of Data Manipulation”.

This package gives us the tools to wrangle, manipulate, and tidy our data with ease.
Check out the dplyr cheatsheet.

Data wrangling by Allison Horst

`dplyr` verbs

filter() – select rows based on their values
arrange() – sort rows based on their values
select() – select columns
mutate() – add new columns by transforming other columns
summarize() – perform summary operations on columns
group_by() – facilitate group-wise operations
Use the pipe operator (|> or %>%) to chain together data wrangling operations.

The Pipe Operator

No matter how complex and polished the individual operations are, it is often the quality of the glue that most directly determines the power of the system.

— Hal Abelson

The Pipe Operator

With dplyr, your code should read like a sentence.

The pipe operator is an important part of that readability.
The data is the primary object in your sentence, so it should come first in your code.

The Pipe Operator

The pipe specifies a sequence of operations.
The output from one operation is passed into the first argument of the next operation.

The original pipe: %>%
- Loaded with tidyverse package (part of magrittr).
The “native” pipe: |>
- Was created in R version 4.1.0.
- Tools > Global Options... > Code > check Use native pipe operator.

The Pipe Operator

dr_rehnberg |>
  do_a_dance()

dr_rehnberg |>
  put_on("cool hat") |>
  do_a_dance(type = "macarena")

Data Comes First!

filter(data = cereal, ...)
select(data = cereal, ...)
mutate(data = cereal, ...)

These are equivalent:

summary(data = cereal)

cereal |> 
  summary()

The pipe operator is your friend!

You can also pipe manipulated data or summaries directly into your ggplot2 code for plotting!

`filter()`

dplyr filter() by Allison Horst

`filter()`

We filter to the rows (observations) we would like to keep in the data.

cereal |> 
  filter(calories <= 100)

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33	68.40297
All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33	59.42551
All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50	93.70491
Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67	49.12025
Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67	53.31381
Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00	45.86332
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00	64.53382
Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75	36.17620
Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75	44.33086
Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80	58.34514
Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88	35.25244
Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88	52.07690
Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67	45.32807
Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00	54.85092
Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00	40.10596
Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00	59.64284
Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00	41.50354
Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00	60.75611
Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00	63.00565
Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50	49.51187
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67	50.82839
Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50	39.70340
Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50	55.33314
Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00	68.23588
Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67	74.47295
Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67	72.80179
Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00	59.36399
Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00	46.65884
Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67	49.78744
Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00	51.59219

`filter()`

We can add multiple filters to our data, to get a more specific subset.

cereal |> 
  filter(calories <= 100,
         type == "hot")

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21	0	-1	0	2	1	1.00	64.53382
Maypo	A	hot	100	4	1	0	0.0	16	3	95	25	2	1	1.00	54.85092
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1	-1	110	0	1	1	0.67	50.82839

`filter()`: Handy Helpers!

> greater than
< less than
== equal to
! not
%in% identifies if an element belongs to a vector
& / , and
| or
is.na() binary evaluation of missing values

`filter()`: `|`

cereal |> 
  filter(calories <= 100,
         type == "hot")

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21	0	-1	0	2	1	1.00	64.53382
Maypo	A	hot	100	4	1	0	0.0	16	3	95	25	2	1	1.00	54.85092
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1	-1	110	0	1	1	0.67	50.82839

What if I wanted either “low calorie” cereals or hot cereals…

Code

cereal |> 
  filter(calories <= 100 |
           type == "hot")

`filter()`: `%in%`

Are you interested in observations with values in a list of levels?

cereal |> 
  filter(name %in% c("Cheerios", "Cinnamon Toast Crunch", "Raisin Bran", "Cracklin' Oat Bran"))

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
Cheerios	G	cold	110	6	2	290	2	17	1	105	25	1	1.00	1.25	50.76500
Cinnamon Toast Crunch	G	cold	120	1	3	210	0	13	9	45	25	2	1.00	0.75	19.82357
Cracklin' Oat Bran	K	cold	110	3	3	140	4	10	7	160	25	3	1.00	0.50	40.44877
Raisin Bran	K	cold	120	3	1	210	5	14	12	240	25	2	1.33	0.75	39.25920

How do we “filter” in base `R`?

You can use the subset() function!

subset(cereal, name %in% c("Cheerios", "Cinnamon Toast Crunch", "Raisin Bran", "Cracklin' Oat Bran"))

	name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
12	Cheerios	G	cold	110	6	2	290	2	17	1	105	25	1	1.00	1.25	50.76500
13	Cinnamon Toast Crunch	G	cold	120	1	3	210	0	13	9	45	25	2	1.00	0.75	19.82357
20	Cracklin' Oat Bran	K	cold	110	3	3	140	4	10	7	160	25	3	1.00	0.50	40.44877
59	Raisin Bran	K	cold	120	3	1	210	5	14	12	240	25	2	1.33	0.75	39.25920

subset(cereal, calories <= 100 & type == "hot")

	name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
21	Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21	0	-1	0	2	1	1.00	64.53382
44	Maypo	A	hot	100	4	1	0	0.0	16	3	95	25	2	1	1.00	54.85092
58	Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1	-1	110	0	1	1	0.67	50.82839

`arrange()`

We arrange the rows of the data in order of a particular variable.

cereal |> 
  arrange(calories)

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50	93.70491
Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00	60.75611
Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00	63.00565
100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33	68.40297
All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33	59.42551
Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00	68.23588
Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67	49.12025
Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67	53.31381
Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00	59.64284
Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50	55.33314
Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67	74.47295
Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67	72.80179
Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00	59.36399
Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00	45.86332
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00	64.53382
Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75	36.17620
Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75	44.33086
Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80	58.34514
Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88	35.25244
Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88	52.07690
Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67	45.32807
Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00	54.85092
Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00	40.10596
Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00	41.50354
Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50	49.51187
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67	50.82839
Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50	39.70340
Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00	46.65884
Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67	49.78744
Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00	51.59219
Almond Delight	R	cold	110	2	2	200	1.0	14.0	8	-1	25	3	1.00	0.75	34.38484
Apple Cinnamon Cheerios	G	cold	110	2	2	180	1.5	10.5	10	70	25	1	1.00	0.75	29.50954
Apple Jacks	K	cold	110	2	0	125	1.0	11.0	14	30	25	2	1.00	1.00	33.17409
Cheerios	G	cold	110	6	2	290	2.0	17.0	1	105	25	1	1.00	1.25	50.76500
Clusters	G	cold	110	3	2	140	2.0	13.0	7	105	25	3	1.00	0.50	40.40021
Cocoa Puffs	G	cold	110	1	1	180	0.0	12.0	13	55	25	2	1.00	1.00	22.73645
Corn Chex	R	cold	110	2	0	280	0.0	22.0	3	25	25	1	1.00	1.00	41.44502
Corn Pops	K	cold	110	1	0	90	1.0	13.0	12	20	25	2	1.00	1.00	35.78279
Count Chocula	G	cold	110	1	1	180	0.0	12.0	13	65	25	2	1.00	1.00	22.39651
Cracklin' Oat Bran	K	cold	110	3	3	140	4.0	10.0	7	160	25	3	1.00	0.50	40.44877
Crispix	K	cold	110	2	0	220	1.0	21.0	3	30	25	3	1.00	1.00	46.89564
Froot Loops	K	cold	110	2	1	125	1.0	11.0	13	30	25	2	1.00	1.00	32.20758
Frosted Flakes	K	cold	110	1	0	200	1.0	14.0	11	25	25	1	1.00	0.75	31.43597
Fruity Pebbles	P	cold	110	1	1	135	0.0	13.0	12	25	25	2	1.00	0.75	28.02576
Golden Grahams	G	cold	110	1	1	280	0.0	15.0	9	45	25	2	1.00	0.75	23.80404
Grape-Nuts	P	cold	110	3	0	170	3.0	17.0	3	90	25	3	1.00	0.25	53.37101
Honey Nut Cheerios	G	cold	110	3	1	250	1.5	11.5	10	90	25	1	1.00	0.75	31.07222
Honey-comb	P	cold	110	1	0	180	0.0	14.0	11	35	25	1	1.00	1.33	28.74241
Just Right Crunchy Nuggets	K	cold	110	2	1	170	1.0	17.0	6	60	100	3	1.00	1.00	36.52368
Kix	G	cold	110	2	1	260	0.0	21.0	3	40	25	2	1.00	1.50	39.24111
Lucky Charms	G	cold	110	2	1	180	0.0	12.0	12	55	25	2	1.00	1.00	26.73451
Rice Chex	R	cold	110	1	0	240	0.0	23.0	2	30	25	1	1.00	1.13	41.99893
Rice Krispies	K	cold	110	2	0	290	0.0	22.0	3	35	25	1	1.00	1.00	40.56016
Smacks	K	cold	110	2	1	70	1.0	9.0	15	40	25	2	1.00	0.75	31.23005
Special K	K	cold	110	6	0	230	1.0	16.0	3	55	25	1	1.00	1.00	53.13132
Total Corn Flakes	G	cold	110	2	1	200	0.0	21.0	3	35	100	3	1.00	1.00	38.83975
Triples	G	cold	110	2	1	250	0.0	21.0	3	60	25	3	1.00	0.75	39.10617
Trix	G	cold	110	1	1	140	0.0	13.0	12	25	25	2	1.00	1.00	27.75330
Wheaties Honey Gold	G	cold	110	2	1	200	1.0	16.0	8	60	25	1	1.00	0.75	36.18756
100% Natural Bran	Q	cold	120	3	5	15	2.0	8.0	8	135	0	3	1.00	1.00	33.98368
Cap'n'Crunch	Q	cold	120	1	2	220	0.0	12.0	12	35	25	2	1.00	0.75	18.04285
Cinnamon Toast Crunch	G	cold	120	1	3	210	0.0	13.0	9	45	25	2	1.00	0.75	19.82357
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	3	2	160	5.0	12.0	10	200	25	3	1.25	0.67	40.91705
Fruitful Bran	K	cold	120	3	0	240	5.0	14.0	12	190	25	3	1.33	0.67	41.01549
Great Grains Pecan	P	cold	120	3	3	75	3.0	13.0	4	100	25	3	1.00	0.33	45.81172
Honey Graham Ohs	Q	cold	120	1	2	220	1.0	12.0	11	45	25	2	1.00	1.00	21.87129
Nut&Honey Crunch	K	cold	120	2	1	190	0.0	15.0	9	40	25	2	1.00	0.67	29.92429
Post Nat. Raisin Bran	P	cold	120	3	1	200	6.0	11.0	14	260	25	3	1.33	0.67	37.84059
Raisin Bran	K	cold	120	3	1	210	5.0	14.0	12	240	25	2	1.33	0.75	39.25920
Basic 4	G	cold	130	3	2	210	2.0	18.0	8	100	25	3	1.33	0.75	37.03856
Oatmeal Raisin Crisp	G	cold	130	3	2	170	1.5	13.5	10	120	25	3	1.25	0.50	30.45084
Just Right Fruit & Nut	K	cold	140	3	1	170	2.0	20.0	9	95	100	3	1.30	0.75	36.47151
Nutri-Grain Almond-Raisin	K	cold	140	3	2	220	3.0	21.0	7	130	25	3	1.33	0.67	40.69232
Total Raisin Bran	G	cold	140	3	1	190	4.0	15.0	14	230	100	3	1.50	1.00	28.59278
Muesli Raisins; Dates; & Almonds	R	cold	150	4	3	95	3.0	16.0	11	170	25	3	1.00	1.00	37.13686
Muesli Raisins; Peaches; & Pecans	R	cold	150	4	3	150	3.0	16.0	11	170	25	3	1.00	1.00	34.13976
Mueslix Crispy Blend	K	cold	160	3	2	150	3.0	17.0	13	160	25	3	1.50	0.67	30.31335

`arrange()`

We can arrange by multiple variables.

cereal |> 
  arrange(calories, sugars) |>
  select(c(1:4, 10))

name	manuf	type	calories	sugars
All-Bran with Extra Fiber	K	cold	50	0
Puffed Rice	Q	cold	50	0
Puffed Wheat	Q	cold	50	0
All-Bran	K	cold	70	5
100% Bran	N	cold	70	6
Shredded Wheat	N	cold	80	0
Shredded Wheat 'n'Bran	N	cold	90	0
Shredded Wheat spoon size	N	cold	90	0
Nutri-grain Wheat	K	cold	90	2
Bran Flakes	P	cold	90	5
Strawberry Fruit Wheats	N	cold	90	5
Bran Chex	R	cold	90	6
Raisin Squares	K	cold	90	6
Quaker Oatmeal	Q	hot	100	-1
Cream of Wheat (Quick)	N	hot	100	0
Corn Flakes	K	cold	100	2
Maypo	A	hot	100	3
Product 19	K	cold	100	3
Total Whole Grain	G	cold	100	3
Wheat Chex	R	cold	100	3
Wheaties	G	cold	100	3
Double Chex	R	cold	100	5
Grape Nuts Flakes	P	cold	100	5
Life	Q	cold	100	6
Multi-Grain Cheerios	G	cold	100	6
Quaker Oat Squares	Q	cold	100	6
Frosted Mini-Wheats	K	cold	100	7
Raisin Nut Bran	G	cold	100	8
Crispy Wheat & Raisins	G	cold	100	10
Golden Crisp	P	cold	100	15
Cheerios	G	cold	110	1
Rice Chex	R	cold	110	2
Corn Chex	R	cold	110	3
Crispix	K	cold	110	3
Grape-Nuts	P	cold	110	3
Kix	G	cold	110	3
Rice Krispies	K	cold	110	3
Special K	K	cold	110	3
Total Corn Flakes	G	cold	110	3
Triples	G	cold	110	3
Just Right Crunchy Nuggets	K	cold	110	6
Clusters	G	cold	110	7
Cracklin' Oat Bran	K	cold	110	7
Almond Delight	R	cold	110	8
Wheaties Honey Gold	G	cold	110	8
Golden Grahams	G	cold	110	9
Apple Cinnamon Cheerios	G	cold	110	10
Honey Nut Cheerios	G	cold	110	10
Frosted Flakes	K	cold	110	11
Honey-comb	P	cold	110	11
Corn Pops	K	cold	110	12
Fruity Pebbles	P	cold	110	12
Lucky Charms	G	cold	110	12
Trix	G	cold	110	12
Cocoa Puffs	G	cold	110	13
Count Chocula	G	cold	110	13
Froot Loops	K	cold	110	13
Apple Jacks	K	cold	110	14
Smacks	K	cold	110	15
Great Grains Pecan	P	cold	120	4
100% Natural Bran	Q	cold	120	8
Cinnamon Toast Crunch	G	cold	120	9
Nut&Honey Crunch	K	cold	120	9
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	10
Honey Graham Ohs	Q	cold	120	11
Cap'n'Crunch	Q	cold	120	12
Fruitful Bran	K	cold	120	12
Raisin Bran	K	cold	120	12
Post Nat. Raisin Bran	P	cold	120	14
Basic 4	G	cold	130	8
Oatmeal Raisin Crisp	G	cold	130	10
Nutri-Grain Almond-Raisin	K	cold	140	7
Just Right Fruit & Nut	K	cold	140	9
Total Raisin Bran	G	cold	140	14
Muesli Raisins; Dates; & Almonds	R	cold	150	11
Muesli Raisins; Peaches; & Pecans	R	cold	150	11
Mueslix Crispy Blend	K	cold	160	13

`arrange()`: Descending Order

Default is ascending order!

cereal |> 
  arrange(calories)

Need to add desc() to get descending order!

cereal |> 
  arrange(desc(calories))

`slice_max()`

Selects the n rows with the maximum values of the specified variable.

cereal |> 
  slice_max(order_by = sugars, n = 3)

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
Golden Crisp	P	cold	100	2	0	45	0	11	15	40	25	1	1.00	0.88	35.25244
Smacks	K	cold	110	2	1	70	1	9	15	40	25	2	1.00	0.75	31.23005
Apple Jacks	K	cold	110	2	0	125	1	11	14	30	25	2	1.00	1.00	33.17409
Post Nat. Raisin Bran	P	cold	120	3	1	200	6	11	14	260	25	3	1.33	0.67	37.84059
Total Raisin Bran	G	cold	140	3	1	190	4	15	14	230	100	3	1.50	1.00	28.59278

cereal |> 
  slice_max(order_by = sugars, n = 3, with_ties = FALSE)

How do we “arrange” in base `R`?

You can use the order() function!

cereal[order(cereal$calories),]

	name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
4	All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50	93.70491
55	Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00	60.75611
56	Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00	63.00565
1	100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33	68.40297
3	All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33	59.42551
64	Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00	68.23588
9	Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67	49.12025
10	Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67	53.31381
51	Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00	59.64284
61	Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50	55.33314
65	Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67	74.47295
66	Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67	72.80179
69	Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00	59.36399
17	Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00	45.86332
21	Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00	64.53382
23	Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75	36.17620
24	Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75	44.33086
27	Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80	58.34514
31	Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88	35.25244
33	Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88	52.07690
42	Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67	45.32807
44	Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00	54.85092
48	Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00	40.10596
54	Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00	41.50354
57	Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50	49.51187
58	Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67	50.82839
60	Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50	39.70340
72	Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00	46.65884
75	Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67	49.78744
76	Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00	51.59219
5	Almond Delight	R	cold	110	2	2	200	1.0	14.0	8	-1	25	3	1.00	0.75	34.38484
6	Apple Cinnamon Cheerios	G	cold	110	2	2	180	1.5	10.5	10	70	25	1	1.00	0.75	29.50954
7	Apple Jacks	K	cold	110	2	0	125	1.0	11.0	14	30	25	2	1.00	1.00	33.17409
12	Cheerios	G	cold	110	6	2	290	2.0	17.0	1	105	25	1	1.00	1.25	50.76500
14	Clusters	G	cold	110	3	2	140	2.0	13.0	7	105	25	3	1.00	0.50	40.40021
15	Cocoa Puffs	G	cold	110	1	1	180	0.0	12.0	13	55	25	2	1.00	1.00	22.73645
16	Corn Chex	R	cold	110	2	0	280	0.0	22.0	3	25	25	1	1.00	1.00	41.44502
18	Corn Pops	K	cold	110	1	0	90	1.0	13.0	12	20	25	2	1.00	1.00	35.78279
19	Count Chocula	G	cold	110	1	1	180	0.0	12.0	13	65	25	2	1.00	1.00	22.39651
20	Cracklin' Oat Bran	K	cold	110	3	3	140	4.0	10.0	7	160	25	3	1.00	0.50	40.44877
22	Crispix	K	cold	110	2	0	220	1.0	21.0	3	30	25	3	1.00	1.00	46.89564
25	Froot Loops	K	cold	110	2	1	125	1.0	11.0	13	30	25	2	1.00	1.00	32.20758
26	Frosted Flakes	K	cold	110	1	0	200	1.0	14.0	11	25	25	1	1.00	0.75	31.43597
30	Fruity Pebbles	P	cold	110	1	1	135	0.0	13.0	12	25	25	2	1.00	0.75	28.02576
32	Golden Grahams	G	cold	110	1	1	280	0.0	15.0	9	45	25	2	1.00	0.75	23.80404
34	Grape-Nuts	P	cold	110	3	0	170	3.0	17.0	3	90	25	3	1.00	0.25	53.37101
37	Honey Nut Cheerios	G	cold	110	3	1	250	1.5	11.5	10	90	25	1	1.00	0.75	31.07222
38	Honey-comb	P	cold	110	1	0	180	0.0	14.0	11	35	25	1	1.00	1.33	28.74241
39	Just Right Crunchy Nuggets	K	cold	110	2	1	170	1.0	17.0	6	60	100	3	1.00	1.00	36.52368
41	Kix	G	cold	110	2	1	260	0.0	21.0	3	40	25	2	1.00	1.50	39.24111
43	Lucky Charms	G	cold	110	2	1	180	0.0	12.0	12	55	25	2	1.00	1.00	26.73451
62	Rice Chex	R	cold	110	1	0	240	0.0	23.0	2	30	25	1	1.00	1.13	41.99893
63	Rice Krispies	K	cold	110	2	0	290	0.0	22.0	3	35	25	1	1.00	1.00	40.56016
67	Smacks	K	cold	110	2	1	70	1.0	9.0	15	40	25	2	1.00	0.75	31.23005
68	Special K	K	cold	110	6	0	230	1.0	16.0	3	55	25	1	1.00	1.00	53.13132
70	Total Corn Flakes	G	cold	110	2	1	200	0.0	21.0	3	35	100	3	1.00	1.00	38.83975
73	Triples	G	cold	110	2	1	250	0.0	21.0	3	60	25	3	1.00	0.75	39.10617
74	Trix	G	cold	110	1	1	140	0.0	13.0	12	25	25	2	1.00	1.00	27.75330
77	Wheaties Honey Gold	G	cold	110	2	1	200	1.0	16.0	8	60	25	1	1.00	0.75	36.18756
2	100% Natural Bran	Q	cold	120	3	5	15	2.0	8.0	8	135	0	3	1.00	1.00	33.98368
11	Cap'n'Crunch	Q	cold	120	1	2	220	0.0	12.0	12	35	25	2	1.00	0.75	18.04285
13	Cinnamon Toast Crunch	G	cold	120	1	3	210	0.0	13.0	9	45	25	2	1.00	0.75	19.82357
28	Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	3	2	160	5.0	12.0	10	200	25	3	1.25	0.67	40.91705
29	Fruitful Bran	K	cold	120	3	0	240	5.0	14.0	12	190	25	3	1.33	0.67	41.01549
35	Great Grains Pecan	P	cold	120	3	3	75	3.0	13.0	4	100	25	3	1.00	0.33	45.81172
36	Honey Graham Ohs	Q	cold	120	1	2	220	1.0	12.0	11	45	25	2	1.00	1.00	21.87129
49	Nut&Honey Crunch	K	cold	120	2	1	190	0.0	15.0	9	40	25	2	1.00	0.67	29.92429
53	Post Nat. Raisin Bran	P	cold	120	3	1	200	6.0	11.0	14	260	25	3	1.33	0.67	37.84059
59	Raisin Bran	K	cold	120	3	1	210	5.0	14.0	12	240	25	2	1.33	0.75	39.25920
8	Basic 4	G	cold	130	3	2	210	2.0	18.0	8	100	25	3	1.33	0.75	37.03856
52	Oatmeal Raisin Crisp	G	cold	130	3	2	170	1.5	13.5	10	120	25	3	1.25	0.50	30.45084
40	Just Right Fruit & Nut	K	cold	140	3	1	170	2.0	20.0	9	95	100	3	1.30	0.75	36.47151
50	Nutri-Grain Almond-Raisin	K	cold	140	3	2	220	3.0	21.0	7	130	25	3	1.33	0.67	40.69232
71	Total Raisin Bran	G	cold	140	3	1	190	4.0	15.0	14	230	100	3	1.50	1.00	28.59278
45	Muesli Raisins; Dates; & Almonds	R	cold	150	4	3	95	3.0	16.0	11	170	25	3	1.00	1.00	37.13686
46	Muesli Raisins; Peaches; & Pecans	R	cold	150	4	3	150	3.0	16.0	11	170	25	3	1.00	1.00	34.13976
47	Mueslix Crispy Blend	K	cold	160	3	2	150	3.0	17.0	13	160	25	3	1.50	0.67	30.31335

cereal[order(cereal$calories, cereal$sugars),]

	name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
4	All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50	93.70491
55	Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00	60.75611
56	Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00	63.00565
3	All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33	59.42551
1	100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33	68.40297
64	Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00	68.23588
65	Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67	74.47295
66	Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67	72.80179
51	Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00	59.64284
10	Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67	53.31381
69	Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00	59.36399
9	Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67	49.12025
61	Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50	55.33314
58	Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67	50.82839
21	Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00	64.53382
17	Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00	45.86332
44	Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00	54.85092
54	Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00	41.50354
72	Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00	46.65884
75	Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67	49.78744
76	Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00	51.59219
24	Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75	44.33086
33	Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88	52.07690
42	Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67	45.32807
48	Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00	40.10596
57	Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50	49.51187
27	Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80	58.34514
60	Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50	39.70340
23	Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75	36.17620
31	Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88	35.25244
12	Cheerios	G	cold	110	6	2	290	2.0	17.0	1	105	25	1	1.00	1.25	50.76500
62	Rice Chex	R	cold	110	1	0	240	0.0	23.0	2	30	25	1	1.00	1.13	41.99893
16	Corn Chex	R	cold	110	2	0	280	0.0	22.0	3	25	25	1	1.00	1.00	41.44502
22	Crispix	K	cold	110	2	0	220	1.0	21.0	3	30	25	3	1.00	1.00	46.89564
34	Grape-Nuts	P	cold	110	3	0	170	3.0	17.0	3	90	25	3	1.00	0.25	53.37101
41	Kix	G	cold	110	2	1	260	0.0	21.0	3	40	25	2	1.00	1.50	39.24111
63	Rice Krispies	K	cold	110	2	0	290	0.0	22.0	3	35	25	1	1.00	1.00	40.56016
68	Special K	K	cold	110	6	0	230	1.0	16.0	3	55	25	1	1.00	1.00	53.13132
70	Total Corn Flakes	G	cold	110	2	1	200	0.0	21.0	3	35	100	3	1.00	1.00	38.83975
73	Triples	G	cold	110	2	1	250	0.0	21.0	3	60	25	3	1.00	0.75	39.10617
39	Just Right Crunchy Nuggets	K	cold	110	2	1	170	1.0	17.0	6	60	100	3	1.00	1.00	36.52368
14	Clusters	G	cold	110	3	2	140	2.0	13.0	7	105	25	3	1.00	0.50	40.40021
20	Cracklin' Oat Bran	K	cold	110	3	3	140	4.0	10.0	7	160	25	3	1.00	0.50	40.44877
5	Almond Delight	R	cold	110	2	2	200	1.0	14.0	8	-1	25	3	1.00	0.75	34.38484
77	Wheaties Honey Gold	G	cold	110	2	1	200	1.0	16.0	8	60	25	1	1.00	0.75	36.18756
32	Golden Grahams	G	cold	110	1	1	280	0.0	15.0	9	45	25	2	1.00	0.75	23.80404
6	Apple Cinnamon Cheerios	G	cold	110	2	2	180	1.5	10.5	10	70	25	1	1.00	0.75	29.50954
37	Honey Nut Cheerios	G	cold	110	3	1	250	1.5	11.5	10	90	25	1	1.00	0.75	31.07222
26	Frosted Flakes	K	cold	110	1	0	200	1.0	14.0	11	25	25	1	1.00	0.75	31.43597
38	Honey-comb	P	cold	110	1	0	180	0.0	14.0	11	35	25	1	1.00	1.33	28.74241
18	Corn Pops	K	cold	110	1	0	90	1.0	13.0	12	20	25	2	1.00	1.00	35.78279
30	Fruity Pebbles	P	cold	110	1	1	135	0.0	13.0	12	25	25	2	1.00	0.75	28.02576
43	Lucky Charms	G	cold	110	2	1	180	0.0	12.0	12	55	25	2	1.00	1.00	26.73451
74	Trix	G	cold	110	1	1	140	0.0	13.0	12	25	25	2	1.00	1.00	27.75330
15	Cocoa Puffs	G	cold	110	1	1	180	0.0	12.0	13	55	25	2	1.00	1.00	22.73645
19	Count Chocula	G	cold	110	1	1	180	0.0	12.0	13	65	25	2	1.00	1.00	22.39651
25	Froot Loops	K	cold	110	2	1	125	1.0	11.0	13	30	25	2	1.00	1.00	32.20758
7	Apple Jacks	K	cold	110	2	0	125	1.0	11.0	14	30	25	2	1.00	1.00	33.17409
67	Smacks	K	cold	110	2	1	70	1.0	9.0	15	40	25	2	1.00	0.75	31.23005
35	Great Grains Pecan	P	cold	120	3	3	75	3.0	13.0	4	100	25	3	1.00	0.33	45.81172
2	100% Natural Bran	Q	cold	120	3	5	15	2.0	8.0	8	135	0	3	1.00	1.00	33.98368
13	Cinnamon Toast Crunch	G	cold	120	1	3	210	0.0	13.0	9	45	25	2	1.00	0.75	19.82357
49	Nut&Honey Crunch	K	cold	120	2	1	190	0.0	15.0	9	40	25	2	1.00	0.67	29.92429
28	Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	3	2	160	5.0	12.0	10	200	25	3	1.25	0.67	40.91705
36	Honey Graham Ohs	Q	cold	120	1	2	220	1.0	12.0	11	45	25	2	1.00	1.00	21.87129
11	Cap'n'Crunch	Q	cold	120	1	2	220	0.0	12.0	12	35	25	2	1.00	0.75	18.04285
29	Fruitful Bran	K	cold	120	3	0	240	5.0	14.0	12	190	25	3	1.33	0.67	41.01549
59	Raisin Bran	K	cold	120	3	1	210	5.0	14.0	12	240	25	2	1.33	0.75	39.25920
53	Post Nat. Raisin Bran	P	cold	120	3	1	200	6.0	11.0	14	260	25	3	1.33	0.67	37.84059
8	Basic 4	G	cold	130	3	2	210	2.0	18.0	8	100	25	3	1.33	0.75	37.03856
52	Oatmeal Raisin Crisp	G	cold	130	3	2	170	1.5	13.5	10	120	25	3	1.25	0.50	30.45084
50	Nutri-Grain Almond-Raisin	K	cold	140	3	2	220	3.0	21.0	7	130	25	3	1.33	0.67	40.69232
40	Just Right Fruit & Nut	K	cold	140	3	1	170	2.0	20.0	9	95	100	3	1.30	0.75	36.47151
71	Total Raisin Bran	G	cold	140	3	1	190	4.0	15.0	14	230	100	3	1.50	1.00	28.59278
45	Muesli Raisins; Dates; & Almonds	R	cold	150	4	3	95	3.0	16.0	11	170	25	3	1.00	1.00	37.13686
46	Muesli Raisins; Peaches; & Pecans	R	cold	150	4	3	150	3.0	16.0	11	170	25	3	1.00	1.00	34.13976
47	Mueslix Crispy Blend	K	cold	160	3	2	150	3.0	17.0	13	160	25	3	1.50	0.67	30.31335

`select()`

We select which variables we would like to remain in the data.

cereal |> 
  select(name, manuf, calories, cups)

name	manuf	calories	cups
100% Bran	N	70	0.33
100% Natural Bran	Q	120	1.00
All-Bran	K	70	0.33
All-Bran with Extra Fiber	K	50	0.50
Almond Delight	R	110	0.75
Apple Cinnamon Cheerios	G	110	0.75
Apple Jacks	K	110	1.00
Basic 4	G	130	0.75
Bran Chex	R	90	0.67
Bran Flakes	P	90	0.67
Cap'n'Crunch	Q	120	0.75
Cheerios	G	110	1.25
Cinnamon Toast Crunch	G	120	0.75
Clusters	G	110	0.50
Cocoa Puffs	G	110	1.00
Corn Chex	R	110	1.00
Corn Flakes	K	100	1.00
Corn Pops	K	110	1.00
Count Chocula	G	110	1.00
Cracklin' Oat Bran	K	110	0.50
Cream of Wheat (Quick)	N	100	1.00
Crispix	K	110	1.00
Crispy Wheat & Raisins	G	100	0.75
Double Chex	R	100	0.75
Froot Loops	K	110	1.00
Frosted Flakes	K	110	0.75
Frosted Mini-Wheats	K	100	0.80
Fruit & Fibre Dates; Walnuts; and Oats	P	120	0.67
Fruitful Bran	K	120	0.67
Fruity Pebbles	P	110	0.75
Golden Crisp	P	100	0.88
Golden Grahams	G	110	0.75
Grape Nuts Flakes	P	100	0.88
Grape-Nuts	P	110	0.25
Great Grains Pecan	P	120	0.33
Honey Graham Ohs	Q	120	1.00
Honey Nut Cheerios	G	110	0.75
Honey-comb	P	110	1.33
Just Right Crunchy Nuggets	K	110	1.00
Just Right Fruit & Nut	K	140	0.75
Kix	G	110	1.50
Life	Q	100	0.67
Lucky Charms	G	110	1.00
Maypo	A	100	1.00
Muesli Raisins; Dates; & Almonds	R	150	1.00
Muesli Raisins; Peaches; & Pecans	R	150	1.00
Mueslix Crispy Blend	K	160	0.67
Multi-Grain Cheerios	G	100	1.00
Nut&Honey Crunch	K	120	0.67
Nutri-Grain Almond-Raisin	K	140	0.67
Nutri-grain Wheat	K	90	1.00
Oatmeal Raisin Crisp	G	130	0.50
Post Nat. Raisin Bran	P	120	0.67
Product 19	K	100	1.00
Puffed Rice	Q	50	1.00
Puffed Wheat	Q	50	1.00
Quaker Oat Squares	Q	100	0.50
Quaker Oatmeal	Q	100	0.67
Raisin Bran	K	120	0.75
Raisin Nut Bran	G	100	0.50
Raisin Squares	K	90	0.50
Rice Chex	R	110	1.13
Rice Krispies	K	110	1.00
Shredded Wheat	N	80	1.00
Shredded Wheat 'n'Bran	N	90	0.67
Shredded Wheat spoon size	N	90	0.67
Smacks	K	110	0.75
Special K	K	110	1.00
Strawberry Fruit Wheats	N	90	1.00
Total Corn Flakes	G	110	1.00
Total Raisin Bran	G	140	1.00
Total Whole Grain	G	100	1.00
Triples	G	110	0.75
Trix	G	110	1.00
Wheat Chex	R	100	0.67
Wheaties	G	100	1.00
Wheaties Honey Gold	G	110	0.75

`select()`

You can use : to select a sequence of columns!

cereal |> 
  select(name:calories)

name	manuf	type	calories
100% Bran	N	cold	70
100% Natural Bran	Q	cold	120
All-Bran	K	cold	70
All-Bran with Extra Fiber	K	cold	50
Almond Delight	R	cold	110
Apple Cinnamon Cheerios	G	cold	110
Apple Jacks	K	cold	110
Basic 4	G	cold	130
Bran Chex	R	cold	90
Bran Flakes	P	cold	90
Cap'n'Crunch	Q	cold	120
Cheerios	G	cold	110
Cinnamon Toast Crunch	G	cold	120
Clusters	G	cold	110
Cocoa Puffs	G	cold	110
Corn Chex	R	cold	110
Corn Flakes	K	cold	100
Corn Pops	K	cold	110
Count Chocula	G	cold	110
Cracklin' Oat Bran	K	cold	110
Cream of Wheat (Quick)	N	hot	100
Crispix	K	cold	110
Crispy Wheat & Raisins	G	cold	100
Double Chex	R	cold	100
Froot Loops	K	cold	110
Frosted Flakes	K	cold	110
Frosted Mini-Wheats	K	cold	100
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120
Fruitful Bran	K	cold	120
Fruity Pebbles	P	cold	110
Golden Crisp	P	cold	100
Golden Grahams	G	cold	110
Grape Nuts Flakes	P	cold	100
Grape-Nuts	P	cold	110
Great Grains Pecan	P	cold	120
Honey Graham Ohs	Q	cold	120
Honey Nut Cheerios	G	cold	110
Honey-comb	P	cold	110
Just Right Crunchy Nuggets	K	cold	110
Just Right Fruit & Nut	K	cold	140
Kix	G	cold	110
Life	Q	cold	100
Lucky Charms	G	cold	110
Maypo	A	hot	100
Muesli Raisins; Dates; & Almonds	R	cold	150
Muesli Raisins; Peaches; & Pecans	R	cold	150
Mueslix Crispy Blend	K	cold	160
Multi-Grain Cheerios	G	cold	100
Nut&Honey Crunch	K	cold	120
Nutri-Grain Almond-Raisin	K	cold	140
Nutri-grain Wheat	K	cold	90
Oatmeal Raisin Crisp	G	cold	130
Post Nat. Raisin Bran	P	cold	120
Product 19	K	cold	100
Puffed Rice	Q	cold	50
Puffed Wheat	Q	cold	50
Quaker Oat Squares	Q	cold	100
Quaker Oatmeal	Q	hot	100
Raisin Bran	K	cold	120
Raisin Nut Bran	G	cold	100
Raisin Squares	K	cold	90
Rice Chex	R	cold	110
Rice Krispies	K	cold	110
Shredded Wheat	N	cold	80
Shredded Wheat 'n'Bran	N	cold	90
Shredded Wheat spoon size	N	cold	90
Smacks	K	cold	110
Special K	K	cold	110
Strawberry Fruit Wheats	N	cold	90
Total Corn Flakes	G	cold	110
Total Raisin Bran	G	cold	140
Total Whole Grain	G	cold	100
Triples	G	cold	110
Trix	G	cold	110
Wheat Chex	R	cold	100
Wheaties	G	cold	100
Wheaties Honey Gold	G	cold	110

You can remove columns from the dataset using a -.

cereal |> 
  select(-rating)

`select()`: Reordering

You can reorder columns inside of select()!

cereal |> 
  select(name, rating, manuf, type, calories, cups, weight,
         everything())

name	rating	manuf	type	calories	cups	weight	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf
100% Bran	68.40297	N	cold	70	0.33	1.00	4	1	130	10.0	5.0	6	280	25	3
100% Natural Bran	33.98368	Q	cold	120	1.00	1.00	3	5	15	2.0	8.0	8	135	0	3
All-Bran	59.42551	K	cold	70	0.33	1.00	4	1	260	9.0	7.0	5	320	25	3
All-Bran with Extra Fiber	93.70491	K	cold	50	0.50	1.00	4	0	140	14.0	8.0	0	330	25	3
Almond Delight	34.38484	R	cold	110	0.75	1.00	2	2	200	1.0	14.0	8	-1	25	3
Apple Cinnamon Cheerios	29.50954	G	cold	110	0.75	1.00	2	2	180	1.5	10.5	10	70	25	1
Apple Jacks	33.17409	K	cold	110	1.00	1.00	2	0	125	1.0	11.0	14	30	25	2
Basic 4	37.03856	G	cold	130	0.75	1.33	3	2	210	2.0	18.0	8	100	25	3
Bran Chex	49.12025	R	cold	90	0.67	1.00	2	1	200	4.0	15.0	6	125	25	1
Bran Flakes	53.31381	P	cold	90	0.67	1.00	3	0	210	5.0	13.0	5	190	25	3
Cap'n'Crunch	18.04285	Q	cold	120	0.75	1.00	1	2	220	0.0	12.0	12	35	25	2
Cheerios	50.76500	G	cold	110	1.25	1.00	6	2	290	2.0	17.0	1	105	25	1
Cinnamon Toast Crunch	19.82357	G	cold	120	0.75	1.00	1	3	210	0.0	13.0	9	45	25	2
Clusters	40.40021	G	cold	110	0.50	1.00	3	2	140	2.0	13.0	7	105	25	3
Cocoa Puffs	22.73645	G	cold	110	1.00	1.00	1	1	180	0.0	12.0	13	55	25	2
Corn Chex	41.44502	R	cold	110	1.00	1.00	2	0	280	0.0	22.0	3	25	25	1
Corn Flakes	45.86332	K	cold	100	1.00	1.00	2	0	290	1.0	21.0	2	35	25	1
Corn Pops	35.78279	K	cold	110	1.00	1.00	1	0	90	1.0	13.0	12	20	25	2
Count Chocula	22.39651	G	cold	110	1.00	1.00	1	1	180	0.0	12.0	13	65	25	2
Cracklin' Oat Bran	40.44877	K	cold	110	0.50	1.00	3	3	140	4.0	10.0	7	160	25	3
Cream of Wheat (Quick)	64.53382	N	hot	100	1.00	1.00	3	0	80	1.0	21.0	0	-1	0	2
Crispix	46.89564	K	cold	110	1.00	1.00	2	0	220	1.0	21.0	3	30	25	3
Crispy Wheat & Raisins	36.17620	G	cold	100	0.75	1.00	2	1	140	2.0	11.0	10	120	25	3
Double Chex	44.33086	R	cold	100	0.75	1.00	2	0	190	1.0	18.0	5	80	25	3
Froot Loops	32.20758	K	cold	110	1.00	1.00	2	1	125	1.0	11.0	13	30	25	2
Frosted Flakes	31.43597	K	cold	110	0.75	1.00	1	0	200	1.0	14.0	11	25	25	1
Frosted Mini-Wheats	58.34514	K	cold	100	0.80	1.00	3	0	0	3.0	14.0	7	100	25	2
Fruit & Fibre Dates; Walnuts; and Oats	40.91705	P	cold	120	0.67	1.25	3	2	160	5.0	12.0	10	200	25	3
Fruitful Bran	41.01549	K	cold	120	0.67	1.33	3	0	240	5.0	14.0	12	190	25	3
Fruity Pebbles	28.02576	P	cold	110	0.75	1.00	1	1	135	0.0	13.0	12	25	25	2
Golden Crisp	35.25244	P	cold	100	0.88	1.00	2	0	45	0.0	11.0	15	40	25	1
Golden Grahams	23.80404	G	cold	110	0.75	1.00	1	1	280	0.0	15.0	9	45	25	2
Grape Nuts Flakes	52.07690	P	cold	100	0.88	1.00	3	1	140	3.0	15.0	5	85	25	3
Grape-Nuts	53.37101	P	cold	110	0.25	1.00	3	0	170	3.0	17.0	3	90	25	3
Great Grains Pecan	45.81172	P	cold	120	0.33	1.00	3	3	75	3.0	13.0	4	100	25	3
Honey Graham Ohs	21.87129	Q	cold	120	1.00	1.00	1	2	220	1.0	12.0	11	45	25	2
Honey Nut Cheerios	31.07222	G	cold	110	0.75	1.00	3	1	250	1.5	11.5	10	90	25	1
Honey-comb	28.74241	P	cold	110	1.33	1.00	1	0	180	0.0	14.0	11	35	25	1
Just Right Crunchy Nuggets	36.52368	K	cold	110	1.00	1.00	2	1	170	1.0	17.0	6	60	100	3
Just Right Fruit & Nut	36.47151	K	cold	140	0.75	1.30	3	1	170	2.0	20.0	9	95	100	3
Kix	39.24111	G	cold	110	1.50	1.00	2	1	260	0.0	21.0	3	40	25	2
Life	45.32807	Q	cold	100	0.67	1.00	4	2	150	2.0	12.0	6	95	25	2
Lucky Charms	26.73451	G	cold	110	1.00	1.00	2	1	180	0.0	12.0	12	55	25	2
Maypo	54.85092	A	hot	100	1.00	1.00	4	1	0	0.0	16.0	3	95	25	2
Muesli Raisins; Dates; & Almonds	37.13686	R	cold	150	1.00	1.00	4	3	95	3.0	16.0	11	170	25	3
Muesli Raisins; Peaches; & Pecans	34.13976	R	cold	150	1.00	1.00	4	3	150	3.0	16.0	11	170	25	3
Mueslix Crispy Blend	30.31335	K	cold	160	0.67	1.50	3	2	150	3.0	17.0	13	160	25	3
Multi-Grain Cheerios	40.10596	G	cold	100	1.00	1.00	2	1	220	2.0	15.0	6	90	25	1
Nut&Honey Crunch	29.92429	K	cold	120	0.67	1.00	2	1	190	0.0	15.0	9	40	25	2
Nutri-Grain Almond-Raisin	40.69232	K	cold	140	0.67	1.33	3	2	220	3.0	21.0	7	130	25	3
Nutri-grain Wheat	59.64284	K	cold	90	1.00	1.00	3	0	170	3.0	18.0	2	90	25	3
Oatmeal Raisin Crisp	30.45084	G	cold	130	0.50	1.25	3	2	170	1.5	13.5	10	120	25	3
Post Nat. Raisin Bran	37.84059	P	cold	120	0.67	1.33	3	1	200	6.0	11.0	14	260	25	3
Product 19	41.50354	K	cold	100	1.00	1.00	3	0	320	1.0	20.0	3	45	100	3
Puffed Rice	60.75611	Q	cold	50	1.00	0.50	1	0	0	0.0	13.0	0	15	0	3
Puffed Wheat	63.00565	Q	cold	50	1.00	0.50	2	0	0	1.0	10.0	0	50	0	3
Quaker Oat Squares	49.51187	Q	cold	100	0.50	1.00	4	1	135	2.0	14.0	6	110	25	3
Quaker Oatmeal	50.82839	Q	hot	100	0.67	1.00	5	2	0	2.7	-1.0	-1	110	0	1
Raisin Bran	39.25920	K	cold	120	0.75	1.33	3	1	210	5.0	14.0	12	240	25	2
Raisin Nut Bran	39.70340	G	cold	100	0.50	1.00	3	2	140	2.5	10.5	8	140	25	3
Raisin Squares	55.33314	K	cold	90	0.50	1.00	2	0	0	2.0	15.0	6	110	25	3
Rice Chex	41.99893	R	cold	110	1.13	1.00	1	0	240	0.0	23.0	2	30	25	1
Rice Krispies	40.56016	K	cold	110	1.00	1.00	2	0	290	0.0	22.0	3	35	25	1
Shredded Wheat	68.23588	N	cold	80	1.00	0.83	2	0	0	3.0	16.0	0	95	0	1
Shredded Wheat 'n'Bran	74.47295	N	cold	90	0.67	1.00	3	0	0	4.0	19.0	0	140	0	1
Shredded Wheat spoon size	72.80179	N	cold	90	0.67	1.00	3	0	0	3.0	20.0	0	120	0	1
Smacks	31.23005	K	cold	110	0.75	1.00	2	1	70	1.0	9.0	15	40	25	2
Special K	53.13132	K	cold	110	1.00	1.00	6	0	230	1.0	16.0	3	55	25	1
Strawberry Fruit Wheats	59.36399	N	cold	90	1.00	1.00	2	0	15	3.0	15.0	5	90	25	2
Total Corn Flakes	38.83975	G	cold	110	1.00	1.00	2	1	200	0.0	21.0	3	35	100	3
Total Raisin Bran	28.59278	G	cold	140	1.00	1.50	3	1	190	4.0	15.0	14	230	100	3
Total Whole Grain	46.65884	G	cold	100	1.00	1.00	3	1	200	3.0	16.0	3	110	100	3
Triples	39.10617	G	cold	110	0.75	1.00	2	1	250	0.0	21.0	3	60	25	3
Trix	27.75330	G	cold	110	1.00	1.00	1	1	140	0.0	13.0	12	25	25	2
Wheat Chex	49.78744	R	cold	100	0.67	1.00	3	1	230	3.0	17.0	3	115	25	1
Wheaties	51.59219	G	cold	100	1.00	1.00	3	1	200	3.0	17.0	3	110	25	1
Wheaties Honey Gold	36.18756	G	cold	110	0.75	1.00	2	1	200	1.0	16.0	8	60	25	1

`select()`: Handy Helpers!

everything() – selects all columns that you have not already specified
starts_with() – selects columns with names that start with the specified string
ends_with() – selects columns with names that end with the specified string
contains() – selects columns with names that contain the specified string

`rename()`

You can rename columns with select(), but all columns not specified will be dropped.
- Using the rename() function is easier!

cereal |> 
  rename(temp = type)

name	manuf	temp	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33	68.40297
100% Natural Bran	Q	cold	120	3	5	15	2.0	8.0	8	135	0	3	1.00	1.00	33.98368
All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33	59.42551
All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50	93.70491
Almond Delight	R	cold	110	2	2	200	1.0	14.0	8	-1	25	3	1.00	0.75	34.38484
Apple Cinnamon Cheerios	G	cold	110	2	2	180	1.5	10.5	10	70	25	1	1.00	0.75	29.50954
Apple Jacks	K	cold	110	2	0	125	1.0	11.0	14	30	25	2	1.00	1.00	33.17409
Basic 4	G	cold	130	3	2	210	2.0	18.0	8	100	25	3	1.33	0.75	37.03856
Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67	49.12025
Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67	53.31381
Cap'n'Crunch	Q	cold	120	1	2	220	0.0	12.0	12	35	25	2	1.00	0.75	18.04285
Cheerios	G	cold	110	6	2	290	2.0	17.0	1	105	25	1	1.00	1.25	50.76500
Cinnamon Toast Crunch	G	cold	120	1	3	210	0.0	13.0	9	45	25	2	1.00	0.75	19.82357
Clusters	G	cold	110	3	2	140	2.0	13.0	7	105	25	3	1.00	0.50	40.40021
Cocoa Puffs	G	cold	110	1	1	180	0.0	12.0	13	55	25	2	1.00	1.00	22.73645
Corn Chex	R	cold	110	2	0	280	0.0	22.0	3	25	25	1	1.00	1.00	41.44502
Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00	45.86332
Corn Pops	K	cold	110	1	0	90	1.0	13.0	12	20	25	2	1.00	1.00	35.78279
Count Chocula	G	cold	110	1	1	180	0.0	12.0	13	65	25	2	1.00	1.00	22.39651
Cracklin' Oat Bran	K	cold	110	3	3	140	4.0	10.0	7	160	25	3	1.00	0.50	40.44877
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00	64.53382
Crispix	K	cold	110	2	0	220	1.0	21.0	3	30	25	3	1.00	1.00	46.89564
Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75	36.17620
Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75	44.33086
Froot Loops	K	cold	110	2	1	125	1.0	11.0	13	30	25	2	1.00	1.00	32.20758
Frosted Flakes	K	cold	110	1	0	200	1.0	14.0	11	25	25	1	1.00	0.75	31.43597
Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80	58.34514
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	3	2	160	5.0	12.0	10	200	25	3	1.25	0.67	40.91705
Fruitful Bran	K	cold	120	3	0	240	5.0	14.0	12	190	25	3	1.33	0.67	41.01549
Fruity Pebbles	P	cold	110	1	1	135	0.0	13.0	12	25	25	2	1.00	0.75	28.02576
Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88	35.25244
Golden Grahams	G	cold	110	1	1	280	0.0	15.0	9	45	25	2	1.00	0.75	23.80404
Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88	52.07690
Grape-Nuts	P	cold	110	3	0	170	3.0	17.0	3	90	25	3	1.00	0.25	53.37101
Great Grains Pecan	P	cold	120	3	3	75	3.0	13.0	4	100	25	3	1.00	0.33	45.81172
Honey Graham Ohs	Q	cold	120	1	2	220	1.0	12.0	11	45	25	2	1.00	1.00	21.87129
Honey Nut Cheerios	G	cold	110	3	1	250	1.5	11.5	10	90	25	1	1.00	0.75	31.07222
Honey-comb	P	cold	110	1	0	180	0.0	14.0	11	35	25	1	1.00	1.33	28.74241
Just Right Crunchy Nuggets	K	cold	110	2	1	170	1.0	17.0	6	60	100	3	1.00	1.00	36.52368
Just Right Fruit & Nut	K	cold	140	3	1	170	2.0	20.0	9	95	100	3	1.30	0.75	36.47151
Kix	G	cold	110	2	1	260	0.0	21.0	3	40	25	2	1.00	1.50	39.24111
Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67	45.32807
Lucky Charms	G	cold	110	2	1	180	0.0	12.0	12	55	25	2	1.00	1.00	26.73451
Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00	54.85092
Muesli Raisins; Dates; & Almonds	R	cold	150	4	3	95	3.0	16.0	11	170	25	3	1.00	1.00	37.13686
Muesli Raisins; Peaches; & Pecans	R	cold	150	4	3	150	3.0	16.0	11	170	25	3	1.00	1.00	34.13976
Mueslix Crispy Blend	K	cold	160	3	2	150	3.0	17.0	13	160	25	3	1.50	0.67	30.31335
Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00	40.10596
Nut&Honey Crunch	K	cold	120	2	1	190	0.0	15.0	9	40	25	2	1.00	0.67	29.92429
Nutri-Grain Almond-Raisin	K	cold	140	3	2	220	3.0	21.0	7	130	25	3	1.33	0.67	40.69232
Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00	59.64284
Oatmeal Raisin Crisp	G	cold	130	3	2	170	1.5	13.5	10	120	25	3	1.25	0.50	30.45084
Post Nat. Raisin Bran	P	cold	120	3	1	200	6.0	11.0	14	260	25	3	1.33	0.67	37.84059
Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00	41.50354
Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00	60.75611
Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00	63.00565
Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50	49.51187
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67	50.82839
Raisin Bran	K	cold	120	3	1	210	5.0	14.0	12	240	25	2	1.33	0.75	39.25920
Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50	39.70340
Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50	55.33314
Rice Chex	R	cold	110	1	0	240	0.0	23.0	2	30	25	1	1.00	1.13	41.99893
Rice Krispies	K	cold	110	2	0	290	0.0	22.0	3	35	25	1	1.00	1.00	40.56016
Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00	68.23588
Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67	74.47295
Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67	72.80179
Smacks	K	cold	110	2	1	70	1.0	9.0	15	40	25	2	1.00	0.75	31.23005
Special K	K	cold	110	6	0	230	1.0	16.0	3	55	25	1	1.00	1.00	53.13132
Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00	59.36399
Total Corn Flakes	G	cold	110	2	1	200	0.0	21.0	3	35	100	3	1.00	1.00	38.83975
Total Raisin Bran	G	cold	140	3	1	190	4.0	15.0	14	230	100	3	1.50	1.00	28.59278
Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00	46.65884
Triples	G	cold	110	2	1	250	0.0	21.0	3	60	25	3	1.00	0.75	39.10617
Trix	G	cold	110	1	1	140	0.0	13.0	12	25	25	2	1.00	1.00	27.75330
Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67	49.78744
Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00	51.59219
Wheaties Honey Gold	G	cold	110	2	1	200	1.0	16.0	8	60	25	1	1.00	0.75	36.18756

How do we “select” in base `R`?

You don’t really use a specific function!

cereal[,c("name", "manuf", "calories", "cups")]

name	manuf	calories	cups
100% Bran	N	70	0.33
100% Natural Bran	Q	120	1.00
All-Bran	K	70	0.33
All-Bran with Extra Fiber	K	50	0.50
Almond Delight	R	110	0.75
Apple Cinnamon Cheerios	G	110	0.75
Apple Jacks	K	110	1.00
Basic 4	G	130	0.75
Bran Chex	R	90	0.67
Bran Flakes	P	90	0.67
Cap'n'Crunch	Q	120	0.75
Cheerios	G	110	1.25
Cinnamon Toast Crunch	G	120	0.75
Clusters	G	110	0.50
Cocoa Puffs	G	110	1.00
Corn Chex	R	110	1.00
Corn Flakes	K	100	1.00
Corn Pops	K	110	1.00
Count Chocula	G	110	1.00
Cracklin' Oat Bran	K	110	0.50
Cream of Wheat (Quick)	N	100	1.00
Crispix	K	110	1.00
Crispy Wheat & Raisins	G	100	0.75
Double Chex	R	100	0.75
Froot Loops	K	110	1.00
Frosted Flakes	K	110	0.75
Frosted Mini-Wheats	K	100	0.80
Fruit & Fibre Dates; Walnuts; and Oats	P	120	0.67
Fruitful Bran	K	120	0.67
Fruity Pebbles	P	110	0.75
Golden Crisp	P	100	0.88
Golden Grahams	G	110	0.75
Grape Nuts Flakes	P	100	0.88
Grape-Nuts	P	110	0.25
Great Grains Pecan	P	120	0.33
Honey Graham Ohs	Q	120	1.00
Honey Nut Cheerios	G	110	0.75
Honey-comb	P	110	1.33
Just Right Crunchy Nuggets	K	110	1.00
Just Right Fruit & Nut	K	140	0.75
Kix	G	110	1.50
Life	Q	100	0.67
Lucky Charms	G	110	1.00
Maypo	A	100	1.00
Muesli Raisins; Dates; & Almonds	R	150	1.00
Muesli Raisins; Peaches; & Pecans	R	150	1.00
Mueslix Crispy Blend	K	160	0.67
Multi-Grain Cheerios	G	100	1.00
Nut&Honey Crunch	K	120	0.67
Nutri-Grain Almond-Raisin	K	140	0.67
Nutri-grain Wheat	K	90	1.00
Oatmeal Raisin Crisp	G	130	0.50
Post Nat. Raisin Bran	P	120	0.67
Product 19	K	100	1.00
Puffed Rice	Q	50	1.00
Puffed Wheat	Q	50	1.00
Quaker Oat Squares	Q	100	0.50
Quaker Oatmeal	Q	100	0.67
Raisin Bran	K	120	0.75
Raisin Nut Bran	G	100	0.50
Raisin Squares	K	90	0.50
Rice Chex	R	110	1.13
Rice Krispies	K	110	1.00
Shredded Wheat	N	80	1.00
Shredded Wheat 'n'Bran	N	90	0.67
Shredded Wheat spoon size	N	90	0.67
Smacks	K	110	0.75
Special K	K	110	1.00
Strawberry Fruit Wheats	N	90	1.00
Total Corn Flakes	G	110	1.00
Total Raisin Bran	G	140	1.00
Total Whole Grain	G	100	1.00
Triples	G	110	0.75
Trix	G	110	1.00
Wheat Chex	R	100	0.67
Wheaties	G	100	1.00
Wheaties Honey Gold	G	110	0.75

subset(cereal, select = -c(rating))

colnames(cereal)[2:4] <- c("maker","temp","cals")

`mutate()`

Mutate (by Allison Horst)

`mutate()`

The data set gets mutated to either include a new variable…

cereal |> 
  mutate(cal_per_cup = calories / cups)

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating	cal_per_cup
100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33	68.40297	212.12121
100% Natural Bran	Q	cold	120	3	5	15	2.0	8.0	8	135	0	3	1.00	1.00	33.98368	120.00000
All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33	59.42551	212.12121
All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50	93.70491	100.00000
Almond Delight	R	cold	110	2	2	200	1.0	14.0	8	-1	25	3	1.00	0.75	34.38484	146.66667
Apple Cinnamon Cheerios	G	cold	110	2	2	180	1.5	10.5	10	70	25	1	1.00	0.75	29.50954	146.66667
Apple Jacks	K	cold	110	2	0	125	1.0	11.0	14	30	25	2	1.00	1.00	33.17409	110.00000
Basic 4	G	cold	130	3	2	210	2.0	18.0	8	100	25	3	1.33	0.75	37.03856	173.33333
Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67	49.12025	134.32836
Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67	53.31381	134.32836
Cap'n'Crunch	Q	cold	120	1	2	220	0.0	12.0	12	35	25	2	1.00	0.75	18.04285	160.00000
Cheerios	G	cold	110	6	2	290	2.0	17.0	1	105	25	1	1.00	1.25	50.76500	88.00000
Cinnamon Toast Crunch	G	cold	120	1	3	210	0.0	13.0	9	45	25	2	1.00	0.75	19.82357	160.00000
Clusters	G	cold	110	3	2	140	2.0	13.0	7	105	25	3	1.00	0.50	40.40021	220.00000
Cocoa Puffs	G	cold	110	1	1	180	0.0	12.0	13	55	25	2	1.00	1.00	22.73645	110.00000
Corn Chex	R	cold	110	2	0	280	0.0	22.0	3	25	25	1	1.00	1.00	41.44502	110.00000
Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00	45.86332	100.00000
Corn Pops	K	cold	110	1	0	90	1.0	13.0	12	20	25	2	1.00	1.00	35.78279	110.00000
Count Chocula	G	cold	110	1	1	180	0.0	12.0	13	65	25	2	1.00	1.00	22.39651	110.00000
Cracklin' Oat Bran	K	cold	110	3	3	140	4.0	10.0	7	160	25	3	1.00	0.50	40.44877	220.00000
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00	64.53382	100.00000
Crispix	K	cold	110	2	0	220	1.0	21.0	3	30	25	3	1.00	1.00	46.89564	110.00000
Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75	36.17620	133.33333
Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75	44.33086	133.33333
Froot Loops	K	cold	110	2	1	125	1.0	11.0	13	30	25	2	1.00	1.00	32.20758	110.00000
Frosted Flakes	K	cold	110	1	0	200	1.0	14.0	11	25	25	1	1.00	0.75	31.43597	146.66667
Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80	58.34514	125.00000
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	3	2	160	5.0	12.0	10	200	25	3	1.25	0.67	40.91705	179.10448
Fruitful Bran	K	cold	120	3	0	240	5.0	14.0	12	190	25	3	1.33	0.67	41.01549	179.10448
Fruity Pebbles	P	cold	110	1	1	135	0.0	13.0	12	25	25	2	1.00	0.75	28.02576	146.66667
Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88	35.25244	113.63636
Golden Grahams	G	cold	110	1	1	280	0.0	15.0	9	45	25	2	1.00	0.75	23.80404	146.66667
Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88	52.07690	113.63636
Grape-Nuts	P	cold	110	3	0	170	3.0	17.0	3	90	25	3	1.00	0.25	53.37101	440.00000
Great Grains Pecan	P	cold	120	3	3	75	3.0	13.0	4	100	25	3	1.00	0.33	45.81172	363.63636
Honey Graham Ohs	Q	cold	120	1	2	220	1.0	12.0	11	45	25	2	1.00	1.00	21.87129	120.00000
Honey Nut Cheerios	G	cold	110	3	1	250	1.5	11.5	10	90	25	1	1.00	0.75	31.07222	146.66667
Honey-comb	P	cold	110	1	0	180	0.0	14.0	11	35	25	1	1.00	1.33	28.74241	82.70677
Just Right Crunchy Nuggets	K	cold	110	2	1	170	1.0	17.0	6	60	100	3	1.00	1.00	36.52368	110.00000
Just Right Fruit & Nut	K	cold	140	3	1	170	2.0	20.0	9	95	100	3	1.30	0.75	36.47151	186.66667
Kix	G	cold	110	2	1	260	0.0	21.0	3	40	25	2	1.00	1.50	39.24111	73.33333
Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67	45.32807	149.25373
Lucky Charms	G	cold	110	2	1	180	0.0	12.0	12	55	25	2	1.00	1.00	26.73451	110.00000
Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00	54.85092	100.00000
Muesli Raisins; Dates; & Almonds	R	cold	150	4	3	95	3.0	16.0	11	170	25	3	1.00	1.00	37.13686	150.00000
Muesli Raisins; Peaches; & Pecans	R	cold	150	4	3	150	3.0	16.0	11	170	25	3	1.00	1.00	34.13976	150.00000
Mueslix Crispy Blend	K	cold	160	3	2	150	3.0	17.0	13	160	25	3	1.50	0.67	30.31335	238.80597
Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00	40.10596	100.00000
Nut&Honey Crunch	K	cold	120	2	1	190	0.0	15.0	9	40	25	2	1.00	0.67	29.92429	179.10448
Nutri-Grain Almond-Raisin	K	cold	140	3	2	220	3.0	21.0	7	130	25	3	1.33	0.67	40.69232	208.95522
Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00	59.64284	90.00000
Oatmeal Raisin Crisp	G	cold	130	3	2	170	1.5	13.5	10	120	25	3	1.25	0.50	30.45084	260.00000
Post Nat. Raisin Bran	P	cold	120	3	1	200	6.0	11.0	14	260	25	3	1.33	0.67	37.84059	179.10448
Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00	41.50354	100.00000
Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00	60.75611	50.00000
Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00	63.00565	50.00000
Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50	49.51187	200.00000
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67	50.82839	149.25373
Raisin Bran	K	cold	120	3	1	210	5.0	14.0	12	240	25	2	1.33	0.75	39.25920	160.00000
Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50	39.70340	200.00000
Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50	55.33314	180.00000
Rice Chex	R	cold	110	1	0	240	0.0	23.0	2	30	25	1	1.00	1.13	41.99893	97.34513
Rice Krispies	K	cold	110	2	0	290	0.0	22.0	3	35	25	1	1.00	1.00	40.56016	110.00000
Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00	68.23588	80.00000
Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67	74.47295	134.32836
Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67	72.80179	134.32836
Smacks	K	cold	110	2	1	70	1.0	9.0	15	40	25	2	1.00	0.75	31.23005	146.66667
Special K	K	cold	110	6	0	230	1.0	16.0	3	55	25	1	1.00	1.00	53.13132	110.00000
Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00	59.36399	90.00000
Total Corn Flakes	G	cold	110	2	1	200	0.0	21.0	3	35	100	3	1.00	1.00	38.83975	110.00000
Total Raisin Bran	G	cold	140	3	1	190	4.0	15.0	14	230	100	3	1.50	1.00	28.59278	140.00000
Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00	46.65884	100.00000
Triples	G	cold	110	2	1	250	0.0	21.0	3	60	25	3	1.00	0.75	39.10617	146.66667
Trix	G	cold	110	1	1	140	0.0	13.0	12	25	25	2	1.00	1.00	27.75330	110.00000
Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67	49.78744	149.25373
Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00	51.59219	100.00000
Wheaties Honey Gold	G	cold	110	2	1	200	1.0	16.0	8	60	25	1	1.00	0.75	36.18756	146.66667

OR revise an existing variable.

cereal |> 
  mutate(shelf = as.factor(shelf))

`mutate()`: Handy Helpers!

if_else() or case_when() – shortcut for if-else loop
as.factor(), as.numeric(), etc. – change variable type
+, -, *, / – basic mathematical operations
%% – modulo (returns the remainder when doing division)

How do we “mutate” in base `R`?

You can define new columns!

cereal$cal_per_cup <- cereal$calories / cereal$cups

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating	cal_per_cup
100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33	68.40297	212.12121
100% Natural Bran	Q	cold	120	3	5	15	2.0	8.0	8	135	0	3	1.00	1.00	33.98368	120.00000
All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33	59.42551	212.12121
All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50	93.70491	100.00000
Almond Delight	R	cold	110	2	2	200	1.0	14.0	8	-1	25	3	1.00	0.75	34.38484	146.66667
Apple Cinnamon Cheerios	G	cold	110	2	2	180	1.5	10.5	10	70	25	1	1.00	0.75	29.50954	146.66667
Apple Jacks	K	cold	110	2	0	125	1.0	11.0	14	30	25	2	1.00	1.00	33.17409	110.00000
Basic 4	G	cold	130	3	2	210	2.0	18.0	8	100	25	3	1.33	0.75	37.03856	173.33333
Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67	49.12025	134.32836
Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67	53.31381	134.32836
Cap'n'Crunch	Q	cold	120	1	2	220	0.0	12.0	12	35	25	2	1.00	0.75	18.04285	160.00000
Cheerios	G	cold	110	6	2	290	2.0	17.0	1	105	25	1	1.00	1.25	50.76500	88.00000
Cinnamon Toast Crunch	G	cold	120	1	3	210	0.0	13.0	9	45	25	2	1.00	0.75	19.82357	160.00000
Clusters	G	cold	110	3	2	140	2.0	13.0	7	105	25	3	1.00	0.50	40.40021	220.00000
Cocoa Puffs	G	cold	110	1	1	180	0.0	12.0	13	55	25	2	1.00	1.00	22.73645	110.00000
Corn Chex	R	cold	110	2	0	280	0.0	22.0	3	25	25	1	1.00	1.00	41.44502	110.00000
Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00	45.86332	100.00000
Corn Pops	K	cold	110	1	0	90	1.0	13.0	12	20	25	2	1.00	1.00	35.78279	110.00000
Count Chocula	G	cold	110	1	1	180	0.0	12.0	13	65	25	2	1.00	1.00	22.39651	110.00000
Cracklin' Oat Bran	K	cold	110	3	3	140	4.0	10.0	7	160	25	3	1.00	0.50	40.44877	220.00000
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00	64.53382	100.00000
Crispix	K	cold	110	2	0	220	1.0	21.0	3	30	25	3	1.00	1.00	46.89564	110.00000
Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75	36.17620	133.33333
Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75	44.33086	133.33333
Froot Loops	K	cold	110	2	1	125	1.0	11.0	13	30	25	2	1.00	1.00	32.20758	110.00000
Frosted Flakes	K	cold	110	1	0	200	1.0	14.0	11	25	25	1	1.00	0.75	31.43597	146.66667
Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80	58.34514	125.00000
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	3	2	160	5.0	12.0	10	200	25	3	1.25	0.67	40.91705	179.10448
Fruitful Bran	K	cold	120	3	0	240	5.0	14.0	12	190	25	3	1.33	0.67	41.01549	179.10448
Fruity Pebbles	P	cold	110	1	1	135	0.0	13.0	12	25	25	2	1.00	0.75	28.02576	146.66667
Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88	35.25244	113.63636
Golden Grahams	G	cold	110	1	1	280	0.0	15.0	9	45	25	2	1.00	0.75	23.80404	146.66667
Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88	52.07690	113.63636
Grape-Nuts	P	cold	110	3	0	170	3.0	17.0	3	90	25	3	1.00	0.25	53.37101	440.00000
Great Grains Pecan	P	cold	120	3	3	75	3.0	13.0	4	100	25	3	1.00	0.33	45.81172	363.63636
Honey Graham Ohs	Q	cold	120	1	2	220	1.0	12.0	11	45	25	2	1.00	1.00	21.87129	120.00000
Honey Nut Cheerios	G	cold	110	3	1	250	1.5	11.5	10	90	25	1	1.00	0.75	31.07222	146.66667
Honey-comb	P	cold	110	1	0	180	0.0	14.0	11	35	25	1	1.00	1.33	28.74241	82.70677
Just Right Crunchy Nuggets	K	cold	110	2	1	170	1.0	17.0	6	60	100	3	1.00	1.00	36.52368	110.00000
Just Right Fruit & Nut	K	cold	140	3	1	170	2.0	20.0	9	95	100	3	1.30	0.75	36.47151	186.66667
Kix	G	cold	110	2	1	260	0.0	21.0	3	40	25	2	1.00	1.50	39.24111	73.33333
Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67	45.32807	149.25373
Lucky Charms	G	cold	110	2	1	180	0.0	12.0	12	55	25	2	1.00	1.00	26.73451	110.00000
Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00	54.85092	100.00000
Muesli Raisins; Dates; & Almonds	R	cold	150	4	3	95	3.0	16.0	11	170	25	3	1.00	1.00	37.13686	150.00000
Muesli Raisins; Peaches; & Pecans	R	cold	150	4	3	150	3.0	16.0	11	170	25	3	1.00	1.00	34.13976	150.00000
Mueslix Crispy Blend	K	cold	160	3	2	150	3.0	17.0	13	160	25	3	1.50	0.67	30.31335	238.80597
Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00	40.10596	100.00000
Nut&Honey Crunch	K	cold	120	2	1	190	0.0	15.0	9	40	25	2	1.00	0.67	29.92429	179.10448
Nutri-Grain Almond-Raisin	K	cold	140	3	2	220	3.0	21.0	7	130	25	3	1.33	0.67	40.69232	208.95522
Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00	59.64284	90.00000
Oatmeal Raisin Crisp	G	cold	130	3	2	170	1.5	13.5	10	120	25	3	1.25	0.50	30.45084	260.00000
Post Nat. Raisin Bran	P	cold	120	3	1	200	6.0	11.0	14	260	25	3	1.33	0.67	37.84059	179.10448
Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00	41.50354	100.00000
Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00	60.75611	50.00000
Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00	63.00565	50.00000
Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50	49.51187	200.00000
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67	50.82839	149.25373
Raisin Bran	K	cold	120	3	1	210	5.0	14.0	12	240	25	2	1.33	0.75	39.25920	160.00000
Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50	39.70340	200.00000
Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50	55.33314	180.00000
Rice Chex	R	cold	110	1	0	240	0.0	23.0	2	30	25	1	1.00	1.13	41.99893	97.34513
Rice Krispies	K	cold	110	2	0	290	0.0	22.0	3	35	25	1	1.00	1.00	40.56016	110.00000
Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00	68.23588	80.00000
Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67	74.47295	134.32836
Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67	72.80179	134.32836
Smacks	K	cold	110	2	1	70	1.0	9.0	15	40	25	2	1.00	0.75	31.23005	146.66667
Special K	K	cold	110	6	0	230	1.0	16.0	3	55	25	1	1.00	1.00	53.13132	110.00000
Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00	59.36399	90.00000
Total Corn Flakes	G	cold	110	2	1	200	0.0	21.0	3	35	100	3	1.00	1.00	38.83975	110.00000
Total Raisin Bran	G	cold	140	3	1	190	4.0	15.0	14	230	100	3	1.50	1.00	28.59278	140.00000
Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00	46.65884	100.00000
Triples	G	cold	110	2	1	250	0.0	21.0	3	60	25	3	1.00	0.75	39.10617	146.66667
Trix	G	cold	110	1	1	140	0.0	13.0	12	25	25	2	1.00	1.00	27.75330	110.00000
Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67	49.78744	149.25373
Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00	51.59219	100.00000
Wheaties Honey Gold	G	cold	110	2	1	200	1.0	16.0	8	60	25	1	1.00	0.75	36.18756	146.66667

OR overwrite old ones!

cereal$shelf <- as.factor(cereal$shelf)

`group_by()`

The ungroup() command is just as important as the group_by() command! (by Allison Horst)

`group_by()`

Separate the data into different groups based on a categorical variable.

The data gets grouped, but nothing happens externally.

cereal |> 
  group_by(type)

# A tibble: 77 × 16
# Groups:   type [2]
   name      manuf type  calories protein   fat sodium fiber carbo sugars potass
   <fct>     <fct> <fct>    <int>   <int> <int>  <int> <dbl> <dbl>  <int>  <int>
 1 100% Bran N     cold        70       4     1    130  10     5        6    280
 2 100% Nat… Q     cold       120       3     5     15   2     8        8    135
 3 All-Bran  K     cold        70       4     1    260   9     7        5    320
 4 All-Bran… K     cold        50       4     0    140  14     8        0    330
 5 Almond D… R     cold       110       2     2    200   1    14        8     -1
 6 Apple Ci… G     cold       110       2     2    180   1.5  10.5     10     70
 7 Apple Ja… K     cold       110       2     0    125   1    11       14     30
 8 Basic 4   G     cold       130       3     2    210   2    18        8    100
 9 Bran Chex R     cold        90       2     1    200   4    15        6    125
10 Bran Fla… P     cold        90       3     0    210   5    13        5    190
# ℹ 67 more rows
# ℹ 5 more variables: vitamins <int>, shelf <int>, weight <dbl>, cups <dbl>,
#   rating <dbl>

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating
100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33	68.40297
100% Natural Bran	Q	cold	120	3	5	15	2.0	8.0	8	135	0	3	1.00	1.00	33.98368
All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33	59.42551
All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50	93.70491
Almond Delight	R	cold	110	2	2	200	1.0	14.0	8	-1	25	3	1.00	0.75	34.38484
Apple Cinnamon Cheerios	G	cold	110	2	2	180	1.5	10.5	10	70	25	1	1.00	0.75	29.50954
Apple Jacks	K	cold	110	2	0	125	1.0	11.0	14	30	25	2	1.00	1.00	33.17409
Basic 4	G	cold	130	3	2	210	2.0	18.0	8	100	25	3	1.33	0.75	37.03856
Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67	49.12025
Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67	53.31381
Cap'n'Crunch	Q	cold	120	1	2	220	0.0	12.0	12	35	25	2	1.00	0.75	18.04285
Cheerios	G	cold	110	6	2	290	2.0	17.0	1	105	25	1	1.00	1.25	50.76500
Cinnamon Toast Crunch	G	cold	120	1	3	210	0.0	13.0	9	45	25	2	1.00	0.75	19.82357
Clusters	G	cold	110	3	2	140	2.0	13.0	7	105	25	3	1.00	0.50	40.40021
Cocoa Puffs	G	cold	110	1	1	180	0.0	12.0	13	55	25	2	1.00	1.00	22.73645
Corn Chex	R	cold	110	2	0	280	0.0	22.0	3	25	25	1	1.00	1.00	41.44502
Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00	45.86332
Corn Pops	K	cold	110	1	0	90	1.0	13.0	12	20	25	2	1.00	1.00	35.78279
Count Chocula	G	cold	110	1	1	180	0.0	12.0	13	65	25	2	1.00	1.00	22.39651
Cracklin' Oat Bran	K	cold	110	3	3	140	4.0	10.0	7	160	25	3	1.00	0.50	40.44877
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00	64.53382
Crispix	K	cold	110	2	0	220	1.0	21.0	3	30	25	3	1.00	1.00	46.89564
Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75	36.17620
Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75	44.33086
Froot Loops	K	cold	110	2	1	125	1.0	11.0	13	30	25	2	1.00	1.00	32.20758
Frosted Flakes	K	cold	110	1	0	200	1.0	14.0	11	25	25	1	1.00	0.75	31.43597
Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80	58.34514
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	3	2	160	5.0	12.0	10	200	25	3	1.25	0.67	40.91705
Fruitful Bran	K	cold	120	3	0	240	5.0	14.0	12	190	25	3	1.33	0.67	41.01549
Fruity Pebbles	P	cold	110	1	1	135	0.0	13.0	12	25	25	2	1.00	0.75	28.02576
Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88	35.25244
Golden Grahams	G	cold	110	1	1	280	0.0	15.0	9	45	25	2	1.00	0.75	23.80404
Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88	52.07690
Grape-Nuts	P	cold	110	3	0	170	3.0	17.0	3	90	25	3	1.00	0.25	53.37101
Great Grains Pecan	P	cold	120	3	3	75	3.0	13.0	4	100	25	3	1.00	0.33	45.81172
Honey Graham Ohs	Q	cold	120	1	2	220	1.0	12.0	11	45	25	2	1.00	1.00	21.87129
Honey Nut Cheerios	G	cold	110	3	1	250	1.5	11.5	10	90	25	1	1.00	0.75	31.07222
Honey-comb	P	cold	110	1	0	180	0.0	14.0	11	35	25	1	1.00	1.33	28.74241
Just Right Crunchy Nuggets	K	cold	110	2	1	170	1.0	17.0	6	60	100	3	1.00	1.00	36.52368
Just Right Fruit & Nut	K	cold	140	3	1	170	2.0	20.0	9	95	100	3	1.30	0.75	36.47151
Kix	G	cold	110	2	1	260	0.0	21.0	3	40	25	2	1.00	1.50	39.24111
Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67	45.32807
Lucky Charms	G	cold	110	2	1	180	0.0	12.0	12	55	25	2	1.00	1.00	26.73451
Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00	54.85092
Muesli Raisins; Dates; & Almonds	R	cold	150	4	3	95	3.0	16.0	11	170	25	3	1.00	1.00	37.13686
Muesli Raisins; Peaches; & Pecans	R	cold	150	4	3	150	3.0	16.0	11	170	25	3	1.00	1.00	34.13976
Mueslix Crispy Blend	K	cold	160	3	2	150	3.0	17.0	13	160	25	3	1.50	0.67	30.31335
Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00	40.10596
Nut&Honey Crunch	K	cold	120	2	1	190	0.0	15.0	9	40	25	2	1.00	0.67	29.92429
Nutri-Grain Almond-Raisin	K	cold	140	3	2	220	3.0	21.0	7	130	25	3	1.33	0.67	40.69232
Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00	59.64284
Oatmeal Raisin Crisp	G	cold	130	3	2	170	1.5	13.5	10	120	25	3	1.25	0.50	30.45084
Post Nat. Raisin Bran	P	cold	120	3	1	200	6.0	11.0	14	260	25	3	1.33	0.67	37.84059
Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00	41.50354
Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00	60.75611
Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00	63.00565
Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50	49.51187
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67	50.82839
Raisin Bran	K	cold	120	3	1	210	5.0	14.0	12	240	25	2	1.33	0.75	39.25920
Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50	39.70340
Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50	55.33314
Rice Chex	R	cold	110	1	0	240	0.0	23.0	2	30	25	1	1.00	1.13	41.99893
Rice Krispies	K	cold	110	2	0	290	0.0	22.0	3	35	25	1	1.00	1.00	40.56016
Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00	68.23588
Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67	74.47295
Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67	72.80179
Smacks	K	cold	110	2	1	70	1.0	9.0	15	40	25	2	1.00	0.75	31.23005
Special K	K	cold	110	6	0	230	1.0	16.0	3	55	25	1	1.00	1.00	53.13132
Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00	59.36399
Total Corn Flakes	G	cold	110	2	1	200	0.0	21.0	3	35	100	3	1.00	1.00	38.83975
Total Raisin Bran	G	cold	140	3	1	190	4.0	15.0	14	230	100	3	1.50	1.00	28.59278
Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00	46.65884
Triples	G	cold	110	2	1	250	0.0	21.0	3	60	25	3	1.00	0.75	39.10617
Trix	G	cold	110	1	1	140	0.0	13.0	12	25	25	2	1.00	1.00	27.75330
Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67	49.78744
Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00	51.59219
Wheaties Honey Gold	G	cold	110	2	1	200	1.0	16.0	8	60	25	1	1.00	0.75	36.18756

`ungroup()`

The ungroup() function will remove the internal grouping in your data.

This is not something that you typically need to do, but if you are getting weird errors downstream from a group_by() statement, try ungrouping your data!

`summarize()`

group_by() is almost always paired with summarize()!

`summarize()`

We can calculate summaries of variables in the data.

cereal |> 
  summarise(mean_calories = mean(calories))

  mean_calories
1      106.8831

Or multiple summaries at the same time.

cereal |> 
summarise(mean_calories = mean(calories),
          num_cereals = n(),
          mean_sugar = mean(sugars))

  mean_calories num_cereals mean_sugar
1      106.8831          77   6.922078

Note

summarize() and summarise() are synonyms!

`summarize()`: Handy Helpers!

mean(), median(), sd(), sum()
min(), max()
n(), n_distinct() – counts the number of (distinct) elements
first(), last(), nth() – extract the first, last, or nth element
across() – apply a function across columns

`group_by() + summarize()`!

goup_by a variable (or multiple variables)
summarize a variable (or multiple variables) within the groups

cereal |> 
  group_by(manuf) |> 
  summarise(mean_calories = mean(calories))

manuf	mean_calories
A	100.00000
G	111.36364
K	108.69565
N	86.66667
P	108.88889
Q	95.00000
R	115.00000

`group_by() + mutate()`!

goup_by a variable (or multiple variables)
mutate a variable (or multiple variables) within the groups

cereal |> 
  group_by(manuf) |> 
  mutate(mean_calories = mean(calories))

name	manuf	type	calories	protein	fat	sodium	fiber	carbo	sugars	potass	vitamins	shelf	weight	cups	rating	mean_calories
100% Bran	N	cold	70	4	1	130	10.0	5.0	6	280	25	3	1.00	0.33	68.40297	86.66667
100% Natural Bran	Q	cold	120	3	5	15	2.0	8.0	8	135	0	3	1.00	1.00	33.98368	95.00000
All-Bran	K	cold	70	4	1	260	9.0	7.0	5	320	25	3	1.00	0.33	59.42551	108.69565
All-Bran with Extra Fiber	K	cold	50	4	0	140	14.0	8.0	0	330	25	3	1.00	0.50	93.70491	108.69565
Almond Delight	R	cold	110	2	2	200	1.0	14.0	8	-1	25	3	1.00	0.75	34.38484	115.00000
Apple Cinnamon Cheerios	G	cold	110	2	2	180	1.5	10.5	10	70	25	1	1.00	0.75	29.50954	111.36364
Apple Jacks	K	cold	110	2	0	125	1.0	11.0	14	30	25	2	1.00	1.00	33.17409	108.69565
Basic 4	G	cold	130	3	2	210	2.0	18.0	8	100	25	3	1.33	0.75	37.03856	111.36364
Bran Chex	R	cold	90	2	1	200	4.0	15.0	6	125	25	1	1.00	0.67	49.12025	115.00000
Bran Flakes	P	cold	90	3	0	210	5.0	13.0	5	190	25	3	1.00	0.67	53.31381	108.88889
Cap'n'Crunch	Q	cold	120	1	2	220	0.0	12.0	12	35	25	2	1.00	0.75	18.04285	95.00000
Cheerios	G	cold	110	6	2	290	2.0	17.0	1	105	25	1	1.00	1.25	50.76500	111.36364
Cinnamon Toast Crunch	G	cold	120	1	3	210	0.0	13.0	9	45	25	2	1.00	0.75	19.82357	111.36364
Clusters	G	cold	110	3	2	140	2.0	13.0	7	105	25	3	1.00	0.50	40.40021	111.36364
Cocoa Puffs	G	cold	110	1	1	180	0.0	12.0	13	55	25	2	1.00	1.00	22.73645	111.36364
Corn Chex	R	cold	110	2	0	280	0.0	22.0	3	25	25	1	1.00	1.00	41.44502	115.00000
Corn Flakes	K	cold	100	2	0	290	1.0	21.0	2	35	25	1	1.00	1.00	45.86332	108.69565
Corn Pops	K	cold	110	1	0	90	1.0	13.0	12	20	25	2	1.00	1.00	35.78279	108.69565
Count Chocula	G	cold	110	1	1	180	0.0	12.0	13	65	25	2	1.00	1.00	22.39651	111.36364
Cracklin' Oat Bran	K	cold	110	3	3	140	4.0	10.0	7	160	25	3	1.00	0.50	40.44877	108.69565
Cream of Wheat (Quick)	N	hot	100	3	0	80	1.0	21.0	0	-1	0	2	1.00	1.00	64.53382	86.66667
Crispix	K	cold	110	2	0	220	1.0	21.0	3	30	25	3	1.00	1.00	46.89564	108.69565
Crispy Wheat & Raisins	G	cold	100	2	1	140	2.0	11.0	10	120	25	3	1.00	0.75	36.17620	111.36364
Double Chex	R	cold	100	2	0	190	1.0	18.0	5	80	25	3	1.00	0.75	44.33086	115.00000
Froot Loops	K	cold	110	2	1	125	1.0	11.0	13	30	25	2	1.00	1.00	32.20758	108.69565
Frosted Flakes	K	cold	110	1	0	200	1.0	14.0	11	25	25	1	1.00	0.75	31.43597	108.69565
Frosted Mini-Wheats	K	cold	100	3	0	0	3.0	14.0	7	100	25	2	1.00	0.80	58.34514	108.69565
Fruit & Fibre Dates; Walnuts; and Oats	P	cold	120	3	2	160	5.0	12.0	10	200	25	3	1.25	0.67	40.91705	108.88889
Fruitful Bran	K	cold	120	3	0	240	5.0	14.0	12	190	25	3	1.33	0.67	41.01549	108.69565
Fruity Pebbles	P	cold	110	1	1	135	0.0	13.0	12	25	25	2	1.00	0.75	28.02576	108.88889
Golden Crisp	P	cold	100	2	0	45	0.0	11.0	15	40	25	1	1.00	0.88	35.25244	108.88889
Golden Grahams	G	cold	110	1	1	280	0.0	15.0	9	45	25	2	1.00	0.75	23.80404	111.36364
Grape Nuts Flakes	P	cold	100	3	1	140	3.0	15.0	5	85	25	3	1.00	0.88	52.07690	108.88889
Grape-Nuts	P	cold	110	3	0	170	3.0	17.0	3	90	25	3	1.00	0.25	53.37101	108.88889
Great Grains Pecan	P	cold	120	3	3	75	3.0	13.0	4	100	25	3	1.00	0.33	45.81172	108.88889
Honey Graham Ohs	Q	cold	120	1	2	220	1.0	12.0	11	45	25	2	1.00	1.00	21.87129	95.00000
Honey Nut Cheerios	G	cold	110	3	1	250	1.5	11.5	10	90	25	1	1.00	0.75	31.07222	111.36364
Honey-comb	P	cold	110	1	0	180	0.0	14.0	11	35	25	1	1.00	1.33	28.74241	108.88889
Just Right Crunchy Nuggets	K	cold	110	2	1	170	1.0	17.0	6	60	100	3	1.00	1.00	36.52368	108.69565
Just Right Fruit & Nut	K	cold	140	3	1	170	2.0	20.0	9	95	100	3	1.30	0.75	36.47151	108.69565
Kix	G	cold	110	2	1	260	0.0	21.0	3	40	25	2	1.00	1.50	39.24111	111.36364
Life	Q	cold	100	4	2	150	2.0	12.0	6	95	25	2	1.00	0.67	45.32807	95.00000
Lucky Charms	G	cold	110	2	1	180	0.0	12.0	12	55	25	2	1.00	1.00	26.73451	111.36364
Maypo	A	hot	100	4	1	0	0.0	16.0	3	95	25	2	1.00	1.00	54.85092	100.00000
Muesli Raisins; Dates; & Almonds	R	cold	150	4	3	95	3.0	16.0	11	170	25	3	1.00	1.00	37.13686	115.00000
Muesli Raisins; Peaches; & Pecans	R	cold	150	4	3	150	3.0	16.0	11	170	25	3	1.00	1.00	34.13976	115.00000
Mueslix Crispy Blend	K	cold	160	3	2	150	3.0	17.0	13	160	25	3	1.50	0.67	30.31335	108.69565
Multi-Grain Cheerios	G	cold	100	2	1	220	2.0	15.0	6	90	25	1	1.00	1.00	40.10596	111.36364
Nut&Honey Crunch	K	cold	120	2	1	190	0.0	15.0	9	40	25	2	1.00	0.67	29.92429	108.69565
Nutri-Grain Almond-Raisin	K	cold	140	3	2	220	3.0	21.0	7	130	25	3	1.33	0.67	40.69232	108.69565
Nutri-grain Wheat	K	cold	90	3	0	170	3.0	18.0	2	90	25	3	1.00	1.00	59.64284	108.69565
Oatmeal Raisin Crisp	G	cold	130	3	2	170	1.5	13.5	10	120	25	3	1.25	0.50	30.45084	111.36364
Post Nat. Raisin Bran	P	cold	120	3	1	200	6.0	11.0	14	260	25	3	1.33	0.67	37.84059	108.88889
Product 19	K	cold	100	3	0	320	1.0	20.0	3	45	100	3	1.00	1.00	41.50354	108.69565
Puffed Rice	Q	cold	50	1	0	0	0.0	13.0	0	15	0	3	0.50	1.00	60.75611	95.00000
Puffed Wheat	Q	cold	50	2	0	0	1.0	10.0	0	50	0	3	0.50	1.00	63.00565	95.00000
Quaker Oat Squares	Q	cold	100	4	1	135	2.0	14.0	6	110	25	3	1.00	0.50	49.51187	95.00000
Quaker Oatmeal	Q	hot	100	5	2	0	2.7	-1.0	-1	110	0	1	1.00	0.67	50.82839	95.00000
Raisin Bran	K	cold	120	3	1	210	5.0	14.0	12	240	25	2	1.33	0.75	39.25920	108.69565
Raisin Nut Bran	G	cold	100	3	2	140	2.5	10.5	8	140	25	3	1.00	0.50	39.70340	111.36364
Raisin Squares	K	cold	90	2	0	0	2.0	15.0	6	110	25	3	1.00	0.50	55.33314	108.69565
Rice Chex	R	cold	110	1	0	240	0.0	23.0	2	30	25	1	1.00	1.13	41.99893	115.00000
Rice Krispies	K	cold	110	2	0	290	0.0	22.0	3	35	25	1	1.00	1.00	40.56016	108.69565
Shredded Wheat	N	cold	80	2	0	0	3.0	16.0	0	95	0	1	0.83	1.00	68.23588	86.66667
Shredded Wheat 'n'Bran	N	cold	90	3	0	0	4.0	19.0	0	140	0	1	1.00	0.67	74.47295	86.66667
Shredded Wheat spoon size	N	cold	90	3	0	0	3.0	20.0	0	120	0	1	1.00	0.67	72.80179	86.66667
Smacks	K	cold	110	2	1	70	1.0	9.0	15	40	25	2	1.00	0.75	31.23005	108.69565
Special K	K	cold	110	6	0	230	1.0	16.0	3	55	25	1	1.00	1.00	53.13132	108.69565
Strawberry Fruit Wheats	N	cold	90	2	0	15	3.0	15.0	5	90	25	2	1.00	1.00	59.36399	86.66667
Total Corn Flakes	G	cold	110	2	1	200	0.0	21.0	3	35	100	3	1.00	1.00	38.83975	111.36364
Total Raisin Bran	G	cold	140	3	1	190	4.0	15.0	14	230	100	3	1.50	1.00	28.59278	111.36364
Total Whole Grain	G	cold	100	3	1	200	3.0	16.0	3	110	100	3	1.00	1.00	46.65884	111.36364
Triples	G	cold	110	2	1	250	0.0	21.0	3	60	25	3	1.00	0.75	39.10617	111.36364
Trix	G	cold	110	1	1	140	0.0	13.0	12	25	25	2	1.00	1.00	27.75330	111.36364
Wheat Chex	R	cold	100	3	1	230	3.0	17.0	3	115	25	1	1.00	0.67	49.78744	115.00000
Wheaties	G	cold	100	3	1	200	3.0	17.0	3	110	25	1	1.00	1.00	51.59219	111.36364
Wheaties Honey Gold	G	cold	110	2	1	200	1.0	16.0	8	60	25	1	1.00	0.75	36.18756	111.36364

Glue it all together!

cereal |> 
  filter(type == "cold") |> 
  mutate(cal_per_cup = calories / cups) |> 
  group_by(manuf) |> 
  summarise(mean_cal_per_cup = mean(cal_per_cup))

manuf	mean_cal_per_cup
G	137.7879
K	145.3518
N	130.1556
P	194.7578
Q	121.3220
R	133.8659

Save your changes!

When you manipulate your data, make sure you assign your new dataset to a variable.

cereal_summary <- cereal |> 
  filter(type == "cold") |> 
  mutate(cal_per_cup = calories / cups) |> 
  group_by(manuf) |> 
  summarise(mean_cal_per_cup = mean(cal_per_cup))

Code Formatting

Similar to ggplot formatting with +, do not continue a line after writing a |>!

Bad Practice
Good Practice

cereal |> group_by(type) |> summarise(mean_calories = mean(calories), num_cereals = n(), mean_sugar = mean(sugars))

cereal |> 
  group_by(type) |> 
  summarise(mean_calories = mean(calories), 
            num_cereals = n(),
            mean_sugar = mean(sugars))

PA 3: Identify the Mystery College

Today you will use the dplyr package to clean some data and then use that cleaned data to figure out what college Ephelia has been accepted to.

Submit the full name of the college Ephelia will attend to the Canvas Quiz.

To do…

PA 3: Identify the Mystery College
- Due Wednesday 1/25 at 8:00am

Wednesday, April 19

Today we will…

Review PA 3: Identify the Mystery College
Extending dplyr verbs
- across()
- if_else()
- case_when()
Implication of Data Ethics
Lab 3: Hip Hop Lyrics
Challenge 3: Published Comparisons & Data Ethics

Extending `dplyr` verbs

Example Data set – Cereal

library(liver)
data(cereal)

Data Structure
Data Head
Data Summary

str(cereal, give.attr = FALSE)

'data.frame':   77 obs. of  16 variables:
 $ name    : Factor w/ 77 levels "100% Bran","100% Natural Bran",..: 1 2 3 4 5 6 7 8 9 10 ...
 $ manuf   : Factor w/ 7 levels "A","G","K","N",..: 4 6 3 3 7 2 3 2 7 5 ...
 $ type    : Factor w/ 2 levels "cold","hot": 1 1 1 1 1 1 1 1 1 1 ...
 $ calories: int  70 120 70 50 110 110 110 130 90 90 ...
 $ protein : int  4 3 4 4 2 2 2 3 2 3 ...
 $ fat     : int  1 5 1 0 2 2 0 2 1 0 ...
 $ sodium  : int  130 15 260 140 200 180 125 210 200 210 ...
 $ fiber   : num  10 2 9 14 1 1.5 1 2 4 5 ...
 $ carbo   : num  5 8 7 8 14 10.5 11 18 15 13 ...
 $ sugars  : int  6 8 5 0 8 10 14 8 6 5 ...
 $ potass  : int  280 135 320 330 -1 70 30 100 125 190 ...
 $ vitamins: int  25 0 25 25 25 25 25 25 25 25 ...
 $ shelf   : int  3 3 3 3 3 1 2 3 1 3 ...
 $ weight  : num  1 1 1 1 1 1 1 1.33 1 1 ...
 $ cups    : num  0.33 1 0.33 0.5 0.75 0.75 1 0.75 0.67 0.67 ...
 $ rating  : num  68.4 34 59.4 93.7 34.4 ...

head(cereal)

                       name manuf type calories protein fat sodium fiber carbo
1                 100% Bran     N cold       70       4   1    130  10.0   5.0
2         100% Natural Bran     Q cold      120       3   5     15   2.0   8.0
3                  All-Bran     K cold       70       4   1    260   9.0   7.0
4 All-Bran with Extra Fiber     K cold       50       4   0    140  14.0   8.0
5            Almond Delight     R cold      110       2   2    200   1.0  14.0
6   Apple Cinnamon Cheerios     G cold      110       2   2    180   1.5  10.5
  sugars potass vitamins shelf weight cups   rating
1      6    280       25     3      1 0.33 68.40297
2      8    135        0     3      1 1.00 33.98368
3      5    320       25     3      1 0.33 59.42551
4      0    330       25     3      1 0.50 93.70491
5      8     -1       25     3      1 0.75 34.38484
6     10     70       25     1      1 0.75 29.50954

summary(cereal)

                        name    manuf    type       calories    
 100% Bran                : 1   A: 1   cold:74   Min.   : 50.0  
 100% Natural Bran        : 1   G:22   hot : 3   1st Qu.:100.0  
 All-Bran                 : 1   K:23             Median :110.0  
 All-Bran with Extra Fiber: 1   N: 6             Mean   :106.9  
 Almond Delight           : 1   P: 9             3rd Qu.:110.0  
 Apple Cinnamon Cheerios  : 1   Q: 8             Max.   :160.0  
 (Other)                  :71   R: 8                            
    protein           fat            sodium          fiber       
 Min.   :1.000   Min.   :0.000   Min.   :  0.0   Min.   : 0.000  
 1st Qu.:2.000   1st Qu.:0.000   1st Qu.:130.0   1st Qu.: 1.000  
 Median :3.000   Median :1.000   Median :180.0   Median : 2.000  
 Mean   :2.545   Mean   :1.013   Mean   :159.7   Mean   : 2.152  
 3rd Qu.:3.000   3rd Qu.:2.000   3rd Qu.:210.0   3rd Qu.: 3.000  
 Max.   :6.000   Max.   :5.000   Max.   :320.0   Max.   :14.000  
                                                                 
     carbo          sugars           potass          vitamins     
 Min.   :-1.0   Min.   :-1.000   Min.   : -1.00   Min.   :  0.00  
 1st Qu.:12.0   1st Qu.: 3.000   1st Qu.: 40.00   1st Qu.: 25.00  
 Median :14.0   Median : 7.000   Median : 90.00   Median : 25.00  
 Mean   :14.6   Mean   : 6.922   Mean   : 96.08   Mean   : 28.25  
 3rd Qu.:17.0   3rd Qu.:11.000   3rd Qu.:120.00   3rd Qu.: 25.00  
 Max.   :23.0   Max.   :15.000   Max.   :330.00   Max.   :100.00  
                                                                  
     shelf           weight          cups           rating     
 Min.   :1.000   Min.   :0.50   Min.   :0.250   Min.   :18.04  
 1st Qu.:1.000   1st Qu.:1.00   1st Qu.:0.670   1st Qu.:33.17  
 Median :2.000   Median :1.00   Median :0.750   Median :40.40  
 Mean   :2.208   Mean   :1.03   Mean   :0.821   Mean   :42.67  
 3rd Qu.:3.000   3rd Qu.:1.00   3rd Qu.:1.000   3rd Qu.:50.83  
 Max.   :3.000   Max.   :1.50   Max.   :1.500   Max.   :93.70

Summarize or mutate multiple columns with `across()`

cereal |> 
  group_by(type) |> 
  summarise(across(.cols = calories:potass, .fns = mean))

# A tibble: 2 × 9
  type  calories protein   fat sodium fiber carbo sugars potass
  <fct>    <dbl>   <dbl> <dbl>  <dbl> <dbl> <dbl>  <dbl>  <dbl>
1 cold      107.    2.49  1.01  165.   2.19  14.7  7.18    97.2
2 hot       100     4     1      26.7  1.23  12    0.667   68

Discritize with `if_else()`

cereal |> 
  mutate(cal_cateory = if_else(calories < 100, "low", "high"), .after = calories)

                                     name manuf type calories cal_cateory
1                               100% Bran     N cold       70         low
2                       100% Natural Bran     Q cold      120        high
3                                All-Bran     K cold       70         low
4               All-Bran with Extra Fiber     K cold       50         low
5                          Almond Delight     R cold      110        high
6                 Apple Cinnamon Cheerios     G cold      110        high
7                             Apple Jacks     K cold      110        high
8                                 Basic 4     G cold      130        high
9                               Bran Chex     R cold       90         low
10                            Bran Flakes     P cold       90         low
11                           Cap'n'Crunch     Q cold      120        high
12                               Cheerios     G cold      110        high
13                  Cinnamon Toast Crunch     G cold      120        high
14                               Clusters     G cold      110        high
15                            Cocoa Puffs     G cold      110        high
16                              Corn Chex     R cold      110        high
17                            Corn Flakes     K cold      100        high
18                              Corn Pops     K cold      110        high
19                          Count Chocula     G cold      110        high
20                     Cracklin' Oat Bran     K cold      110        high
21                 Cream of Wheat (Quick)     N  hot      100        high
22                                Crispix     K cold      110        high
23                 Crispy Wheat & Raisins     G cold      100        high
24                            Double Chex     R cold      100        high
25                            Froot Loops     K cold      110        high
26                         Frosted Flakes     K cold      110        high
27                    Frosted Mini-Wheats     K cold      100        high
28 Fruit & Fibre Dates; Walnuts; and Oats     P cold      120        high
29                          Fruitful Bran     K cold      120        high
30                         Fruity Pebbles     P cold      110        high
31                           Golden Crisp     P cold      100        high
32                         Golden Grahams     G cold      110        high
33                      Grape Nuts Flakes     P cold      100        high
34                             Grape-Nuts     P cold      110        high
35                     Great Grains Pecan     P cold      120        high
36                       Honey Graham Ohs     Q cold      120        high
37                     Honey Nut Cheerios     G cold      110        high
38                             Honey-comb     P cold      110        high
39            Just Right Crunchy  Nuggets     K cold      110        high
40                 Just Right Fruit & Nut     K cold      140        high
41                                    Kix     G cold      110        high
42                                   Life     Q cold      100        high
43                           Lucky Charms     G cold      110        high
44                                  Maypo     A  hot      100        high
45       Muesli Raisins; Dates; & Almonds     R cold      150        high
46      Muesli Raisins; Peaches; & Pecans     R cold      150        high
47                   Mueslix Crispy Blend     K cold      160        high
48                   Multi-Grain Cheerios     G cold      100        high
49                       Nut&Honey Crunch     K cold      120        high
50              Nutri-Grain Almond-Raisin     K cold      140        high
51                      Nutri-grain Wheat     K cold       90         low
52                   Oatmeal Raisin Crisp     G cold      130        high
53                  Post Nat. Raisin Bran     P cold      120        high
54                             Product 19     K cold      100        high
55                            Puffed Rice     Q cold       50         low
56                           Puffed Wheat     Q cold       50         low
57                     Quaker Oat Squares     Q cold      100        high
58                         Quaker Oatmeal     Q  hot      100        high
59                            Raisin Bran     K cold      120        high
60                        Raisin Nut Bran     G cold      100        high
61                         Raisin Squares     K cold       90         low
62                              Rice Chex     R cold      110        high
63                          Rice Krispies     K cold      110        high
64                         Shredded Wheat     N cold       80         low
65                 Shredded Wheat 'n'Bran     N cold       90         low
66              Shredded Wheat spoon size     N cold       90         low
67                                 Smacks     K cold      110        high
68                              Special K     K cold      110        high
69                Strawberry Fruit Wheats     N cold       90         low
70                      Total Corn Flakes     G cold      110        high
71                      Total Raisin Bran     G cold      140        high
72                      Total Whole Grain     G cold      100        high
73                                Triples     G cold      110        high
74                                   Trix     G cold      110        high
75                             Wheat Chex     R cold      100        high
76                               Wheaties     G cold      100        high
77                    Wheaties Honey Gold     G cold      110        high
   protein fat sodium fiber carbo sugars potass vitamins shelf weight cups
1        4   1    130  10.0   5.0      6    280       25     3   1.00 0.33
2        3   5     15   2.0   8.0      8    135        0     3   1.00 1.00
3        4   1    260   9.0   7.0      5    320       25     3   1.00 0.33
4        4   0    140  14.0   8.0      0    330       25     3   1.00 0.50
5        2   2    200   1.0  14.0      8     -1       25     3   1.00 0.75
6        2   2    180   1.5  10.5     10     70       25     1   1.00 0.75
7        2   0    125   1.0  11.0     14     30       25     2   1.00 1.00
8        3   2    210   2.0  18.0      8    100       25     3   1.33 0.75
9        2   1    200   4.0  15.0      6    125       25     1   1.00 0.67
10       3   0    210   5.0  13.0      5    190       25     3   1.00 0.67
11       1   2    220   0.0  12.0     12     35       25     2   1.00 0.75
12       6   2    290   2.0  17.0      1    105       25     1   1.00 1.25
13       1   3    210   0.0  13.0      9     45       25     2   1.00 0.75
14       3   2    140   2.0  13.0      7    105       25     3   1.00 0.50
15       1   1    180   0.0  12.0     13     55       25     2   1.00 1.00
16       2   0    280   0.0  22.0      3     25       25     1   1.00 1.00
17       2   0    290   1.0  21.0      2     35       25     1   1.00 1.00
18       1   0     90   1.0  13.0     12     20       25     2   1.00 1.00
19       1   1    180   0.0  12.0     13     65       25     2   1.00 1.00
20       3   3    140   4.0  10.0      7    160       25     3   1.00 0.50
21       3   0     80   1.0  21.0      0     -1        0     2   1.00 1.00
22       2   0    220   1.0  21.0      3     30       25     3   1.00 1.00
23       2   1    140   2.0  11.0     10    120       25     3   1.00 0.75
24       2   0    190   1.0  18.0      5     80       25     3   1.00 0.75
25       2   1    125   1.0  11.0     13     30       25     2   1.00 1.00
26       1   0    200   1.0  14.0     11     25       25     1   1.00 0.75
27       3   0      0   3.0  14.0      7    100       25     2   1.00 0.80
28       3   2    160   5.0  12.0     10    200       25     3   1.25 0.67
29       3   0    240   5.0  14.0     12    190       25     3   1.33 0.67
30       1   1    135   0.0  13.0     12     25       25     2   1.00 0.75
31       2   0     45   0.0  11.0     15     40       25     1   1.00 0.88
32       1   1    280   0.0  15.0      9     45       25     2   1.00 0.75
33       3   1    140   3.0  15.0      5     85       25     3   1.00 0.88
34       3   0    170   3.0  17.0      3     90       25     3   1.00 0.25
35       3   3     75   3.0  13.0      4    100       25     3   1.00 0.33
36       1   2    220   1.0  12.0     11     45       25     2   1.00 1.00
37       3   1    250   1.5  11.5     10     90       25     1   1.00 0.75
38       1   0    180   0.0  14.0     11     35       25     1   1.00 1.33
39       2   1    170   1.0  17.0      6     60      100     3   1.00 1.00
40       3   1    170   2.0  20.0      9     95      100     3   1.30 0.75
41       2   1    260   0.0  21.0      3     40       25     2   1.00 1.50
42       4   2    150   2.0  12.0      6     95       25     2   1.00 0.67
43       2   1    180   0.0  12.0     12     55       25     2   1.00 1.00
44       4   1      0   0.0  16.0      3     95       25     2   1.00 1.00
45       4   3     95   3.0  16.0     11    170       25     3   1.00 1.00
46       4   3    150   3.0  16.0     11    170       25     3   1.00 1.00
47       3   2    150   3.0  17.0     13    160       25     3   1.50 0.67
48       2   1    220   2.0  15.0      6     90       25     1   1.00 1.00
49       2   1    190   0.0  15.0      9     40       25     2   1.00 0.67
50       3   2    220   3.0  21.0      7    130       25     3   1.33 0.67
51       3   0    170   3.0  18.0      2     90       25     3   1.00 1.00
52       3   2    170   1.5  13.5     10    120       25     3   1.25 0.50
53       3   1    200   6.0  11.0     14    260       25     3   1.33 0.67
54       3   0    320   1.0  20.0      3     45      100     3   1.00 1.00
55       1   0      0   0.0  13.0      0     15        0     3   0.50 1.00
56       2   0      0   1.0  10.0      0     50        0     3   0.50 1.00
57       4   1    135   2.0  14.0      6    110       25     3   1.00 0.50
58       5   2      0   2.7  -1.0     -1    110        0     1   1.00 0.67
59       3   1    210   5.0  14.0     12    240       25     2   1.33 0.75
60       3   2    140   2.5  10.5      8    140       25     3   1.00 0.50
61       2   0      0   2.0  15.0      6    110       25     3   1.00 0.50
62       1   0    240   0.0  23.0      2     30       25     1   1.00 1.13
63       2   0    290   0.0  22.0      3     35       25     1   1.00 1.00
64       2   0      0   3.0  16.0      0     95        0     1   0.83 1.00
65       3   0      0   4.0  19.0      0    140        0     1   1.00 0.67
66       3   0      0   3.0  20.0      0    120        0     1   1.00 0.67
67       2   1     70   1.0   9.0     15     40       25     2   1.00 0.75
68       6   0    230   1.0  16.0      3     55       25     1   1.00 1.00
69       2   0     15   3.0  15.0      5     90       25     2   1.00 1.00
70       2   1    200   0.0  21.0      3     35      100     3   1.00 1.00
71       3   1    190   4.0  15.0     14    230      100     3   1.50 1.00
72       3   1    200   3.0  16.0      3    110      100     3   1.00 1.00
73       2   1    250   0.0  21.0      3     60       25     3   1.00 0.75
74       1   1    140   0.0  13.0     12     25       25     2   1.00 1.00
75       3   1    230   3.0  17.0      3    115       25     1   1.00 0.67
76       3   1    200   3.0  17.0      3    110       25     1   1.00 1.00
77       2   1    200   1.0  16.0      8     60       25     1   1.00 0.75
     rating
1  68.40297
2  33.98368
3  59.42551
4  93.70491
5  34.38484
6  29.50954
7  33.17409
8  37.03856
9  49.12025
10 53.31381
11 18.04285
12 50.76500
13 19.82357
14 40.40021
15 22.73645
16 41.44502
17 45.86332
18 35.78279
19 22.39651
20 40.44877
21 64.53382
22 46.89564
23 36.17620
24 44.33086
25 32.20758
26 31.43597
27 58.34514
28 40.91705
29 41.01549
30 28.02576
31 35.25244
32 23.80404
33 52.07690
34 53.37101
35 45.81172
36 21.87129
37 31.07222
38 28.74241
39 36.52368
40 36.47151
41 39.24111
42 45.32807
43 26.73451
44 54.85092
45 37.13686
46 34.13976
47 30.31335
48 40.10596
49 29.92429
50 40.69232
51 59.64284
52 30.45084
53 37.84059
54 41.50354
55 60.75611
56 63.00565
57 49.51187
58 50.82839
59 39.25920
60 39.70340
61 55.33314
62 41.99893
63 40.56016
64 68.23588
65 74.47295
66 72.80179
67 31.23005
68 53.13132
69 59.36399
70 38.83975
71 28.59278
72 46.65884
73 39.10617
74 27.75330
75 49.78744
76 51.59219
77 36.18756

Re-leveling with `case_when()`

cereal |> 
  mutate(manuf = case_when(manuf == "A" ~ "American Home Food Products", 
                           manuf == "G" ~ "General Mills", 
                           manuf == "K" ~ "Kelloggs", 
                           manuf == "N" ~ "Nabisco", 
                           manuf == "P" ~ "Post", 
                           manuf == "Q" ~ "Quaker Oats", 
                           manuf == "R" ~ "Ralston Purina"
                           )
  )

                                     name                       manuf type
1                               100% Bran                     Nabisco cold
2                       100% Natural Bran                 Quaker Oats cold
3                                All-Bran                    Kelloggs cold
4               All-Bran with Extra Fiber                    Kelloggs cold
5                          Almond Delight              Ralston Purina cold
6                 Apple Cinnamon Cheerios               General Mills cold
7                             Apple Jacks                    Kelloggs cold
8                                 Basic 4               General Mills cold
9                               Bran Chex              Ralston Purina cold
10                            Bran Flakes                        Post cold
11                           Cap'n'Crunch                 Quaker Oats cold
12                               Cheerios               General Mills cold
13                  Cinnamon Toast Crunch               General Mills cold
14                               Clusters               General Mills cold
15                            Cocoa Puffs               General Mills cold
16                              Corn Chex              Ralston Purina cold
17                            Corn Flakes                    Kelloggs cold
18                              Corn Pops                    Kelloggs cold
19                          Count Chocula               General Mills cold
20                     Cracklin' Oat Bran                    Kelloggs cold
21                 Cream of Wheat (Quick)                     Nabisco  hot
22                                Crispix                    Kelloggs cold
23                 Crispy Wheat & Raisins               General Mills cold
24                            Double Chex              Ralston Purina cold
25                            Froot Loops                    Kelloggs cold
26                         Frosted Flakes                    Kelloggs cold
27                    Frosted Mini-Wheats                    Kelloggs cold
28 Fruit & Fibre Dates; Walnuts; and Oats                        Post cold
29                          Fruitful Bran                    Kelloggs cold
30                         Fruity Pebbles                        Post cold
31                           Golden Crisp                        Post cold
32                         Golden Grahams               General Mills cold
33                      Grape Nuts Flakes                        Post cold
34                             Grape-Nuts                        Post cold
35                     Great Grains Pecan                        Post cold
36                       Honey Graham Ohs                 Quaker Oats cold
37                     Honey Nut Cheerios               General Mills cold
38                             Honey-comb                        Post cold
39            Just Right Crunchy  Nuggets                    Kelloggs cold
40                 Just Right Fruit & Nut                    Kelloggs cold
41                                    Kix               General Mills cold
42                                   Life                 Quaker Oats cold
43                           Lucky Charms               General Mills cold
44                                  Maypo American Home Food Products  hot
45       Muesli Raisins; Dates; & Almonds              Ralston Purina cold
46      Muesli Raisins; Peaches; & Pecans              Ralston Purina cold
47                   Mueslix Crispy Blend                    Kelloggs cold
48                   Multi-Grain Cheerios               General Mills cold
49                       Nut&Honey Crunch                    Kelloggs cold
50              Nutri-Grain Almond-Raisin                    Kelloggs cold
51                      Nutri-grain Wheat                    Kelloggs cold
52                   Oatmeal Raisin Crisp               General Mills cold
53                  Post Nat. Raisin Bran                        Post cold
54                             Product 19                    Kelloggs cold
55                            Puffed Rice                 Quaker Oats cold
56                           Puffed Wheat                 Quaker Oats cold
57                     Quaker Oat Squares                 Quaker Oats cold
58                         Quaker Oatmeal                 Quaker Oats  hot
59                            Raisin Bran                    Kelloggs cold
60                        Raisin Nut Bran               General Mills cold
61                         Raisin Squares                    Kelloggs cold
62                              Rice Chex              Ralston Purina cold
63                          Rice Krispies                    Kelloggs cold
64                         Shredded Wheat                     Nabisco cold
65                 Shredded Wheat 'n'Bran                     Nabisco cold
66              Shredded Wheat spoon size                     Nabisco cold
67                                 Smacks                    Kelloggs cold
68                              Special K                    Kelloggs cold
69                Strawberry Fruit Wheats                     Nabisco cold
70                      Total Corn Flakes               General Mills cold
71                      Total Raisin Bran               General Mills cold
72                      Total Whole Grain               General Mills cold
73                                Triples               General Mills cold
74                                   Trix               General Mills cold
75                             Wheat Chex              Ralston Purina cold
76                               Wheaties               General Mills cold
77                    Wheaties Honey Gold               General Mills cold
   calories protein fat sodium fiber carbo sugars potass vitamins shelf weight
1        70       4   1    130  10.0   5.0      6    280       25     3   1.00
2       120       3   5     15   2.0   8.0      8    135        0     3   1.00
3        70       4   1    260   9.0   7.0      5    320       25     3   1.00
4        50       4   0    140  14.0   8.0      0    330       25     3   1.00
5       110       2   2    200   1.0  14.0      8     -1       25     3   1.00
6       110       2   2    180   1.5  10.5     10     70       25     1   1.00
7       110       2   0    125   1.0  11.0     14     30       25     2   1.00
8       130       3   2    210   2.0  18.0      8    100       25     3   1.33
9        90       2   1    200   4.0  15.0      6    125       25     1   1.00
10       90       3   0    210   5.0  13.0      5    190       25     3   1.00
11      120       1   2    220   0.0  12.0     12     35       25     2   1.00
12      110       6   2    290   2.0  17.0      1    105       25     1   1.00
13      120       1   3    210   0.0  13.0      9     45       25     2   1.00
14      110       3   2    140   2.0  13.0      7    105       25     3   1.00
15      110       1   1    180   0.0  12.0     13     55       25     2   1.00
16      110       2   0    280   0.0  22.0      3     25       25     1   1.00
17      100       2   0    290   1.0  21.0      2     35       25     1   1.00
18      110       1   0     90   1.0  13.0     12     20       25     2   1.00
19      110       1   1    180   0.0  12.0     13     65       25     2   1.00
20      110       3   3    140   4.0  10.0      7    160       25     3   1.00
21      100       3   0     80   1.0  21.0      0     -1        0     2   1.00
22      110       2   0    220   1.0  21.0      3     30       25     3   1.00
23      100       2   1    140   2.0  11.0     10    120       25     3   1.00
24      100       2   0    190   1.0  18.0      5     80       25     3   1.00
25      110       2   1    125   1.0  11.0     13     30       25     2   1.00
26      110       1   0    200   1.0  14.0     11     25       25     1   1.00
27      100       3   0      0   3.0  14.0      7    100       25     2   1.00
28      120       3   2    160   5.0  12.0     10    200       25     3   1.25
29      120       3   0    240   5.0  14.0     12    190       25     3   1.33
30      110       1   1    135   0.0  13.0     12     25       25     2   1.00
31      100       2   0     45   0.0  11.0     15     40       25     1   1.00
32      110       1   1    280   0.0  15.0      9     45       25     2   1.00
33      100       3   1    140   3.0  15.0      5     85       25     3   1.00
34      110       3   0    170   3.0  17.0      3     90       25     3   1.00
35      120       3   3     75   3.0  13.0      4    100       25     3   1.00
36      120       1   2    220   1.0  12.0     11     45       25     2   1.00
37      110       3   1    250   1.5  11.5     10     90       25     1   1.00
38      110       1   0    180   0.0  14.0     11     35       25     1   1.00
39      110       2   1    170   1.0  17.0      6     60      100     3   1.00
40      140       3   1    170   2.0  20.0      9     95      100     3   1.30
41      110       2   1    260   0.0  21.0      3     40       25     2   1.00
42      100       4   2    150   2.0  12.0      6     95       25     2   1.00
43      110       2   1    180   0.0  12.0     12     55       25     2   1.00
44      100       4   1      0   0.0  16.0      3     95       25     2   1.00
45      150       4   3     95   3.0  16.0     11    170       25     3   1.00
46      150       4   3    150   3.0  16.0     11    170       25     3   1.00
47      160       3   2    150   3.0  17.0     13    160       25     3   1.50
48      100       2   1    220   2.0  15.0      6     90       25     1   1.00
49      120       2   1    190   0.0  15.0      9     40       25     2   1.00
50      140       3   2    220   3.0  21.0      7    130       25     3   1.33
51       90       3   0    170   3.0  18.0      2     90       25     3   1.00
52      130       3   2    170   1.5  13.5     10    120       25     3   1.25
53      120       3   1    200   6.0  11.0     14    260       25     3   1.33
54      100       3   0    320   1.0  20.0      3     45      100     3   1.00
55       50       1   0      0   0.0  13.0      0     15        0     3   0.50
56       50       2   0      0   1.0  10.0      0     50        0     3   0.50
57      100       4   1    135   2.0  14.0      6    110       25     3   1.00
58      100       5   2      0   2.7  -1.0     -1    110        0     1   1.00
59      120       3   1    210   5.0  14.0     12    240       25     2   1.33
60      100       3   2    140   2.5  10.5      8    140       25     3   1.00
61       90       2   0      0   2.0  15.0      6    110       25     3   1.00
62      110       1   0    240   0.0  23.0      2     30       25     1   1.00
63      110       2   0    290   0.0  22.0      3     35       25     1   1.00
64       80       2   0      0   3.0  16.0      0     95        0     1   0.83
65       90       3   0      0   4.0  19.0      0    140        0     1   1.00
66       90       3   0      0   3.0  20.0      0    120        0     1   1.00
67      110       2   1     70   1.0   9.0     15     40       25     2   1.00
68      110       6   0    230   1.0  16.0      3     55       25     1   1.00
69       90       2   0     15   3.0  15.0      5     90       25     2   1.00
70      110       2   1    200   0.0  21.0      3     35      100     3   1.00
71      140       3   1    190   4.0  15.0     14    230      100     3   1.50
72      100       3   1    200   3.0  16.0      3    110      100     3   1.00
73      110       2   1    250   0.0  21.0      3     60       25     3   1.00
74      110       1   1    140   0.0  13.0     12     25       25     2   1.00
75      100       3   1    230   3.0  17.0      3    115       25     1   1.00
76      100       3   1    200   3.0  17.0      3    110       25     1   1.00
77      110       2   1    200   1.0  16.0      8     60       25     1   1.00
   cups   rating
1  0.33 68.40297
2  1.00 33.98368
3  0.33 59.42551
4  0.50 93.70491
5  0.75 34.38484
6  0.75 29.50954
7  1.00 33.17409
8  0.75 37.03856
9  0.67 49.12025
10 0.67 53.31381
11 0.75 18.04285
12 1.25 50.76500
13 0.75 19.82357
14 0.50 40.40021
15 1.00 22.73645
16 1.00 41.44502
17 1.00 45.86332
18 1.00 35.78279
19 1.00 22.39651
20 0.50 40.44877
21 1.00 64.53382
22 1.00 46.89564
23 0.75 36.17620
24 0.75 44.33086
25 1.00 32.20758
26 0.75 31.43597
27 0.80 58.34514
28 0.67 40.91705
29 0.67 41.01549
30 0.75 28.02576
31 0.88 35.25244
32 0.75 23.80404
33 0.88 52.07690
34 0.25 53.37101
35 0.33 45.81172
36 1.00 21.87129
37 0.75 31.07222
38 1.33 28.74241
39 1.00 36.52368
40 0.75 36.47151
41 1.50 39.24111
42 0.67 45.32807
43 1.00 26.73451
44 1.00 54.85092
45 1.00 37.13686
46 1.00 34.13976
47 0.67 30.31335
48 1.00 40.10596
49 0.67 29.92429
50 0.67 40.69232
51 1.00 59.64284
52 0.50 30.45084
53 0.67 37.84059
54 1.00 41.50354
55 1.00 60.75611
56 1.00 63.00565
57 0.50 49.51187
58 0.67 50.82839
59 0.75 39.25920
60 0.50 39.70340
61 0.50 55.33314
62 1.13 41.99893
63 1.00 40.56016
64 1.00 68.23588
65 0.67 74.47295
66 0.67 72.80179
67 0.75 31.23005
68 1.00 53.13132
69 1.00 59.36399
70 1.00 38.83975
71 1.00 28.59278
72 1.00 46.65884
73 0.75 39.10617
74 1.00 27.75330
75 0.67 49.78744
76 1.00 51.59219
77 0.75 36.18756

`group_by()` + `slice()`

cereal |> 
  group_by(manuf) |> 
  slice_max(order_by = calories)

# A tibble: 12 × 16
# Groups:   manuf [7]
   name      manuf type  calories protein   fat sodium fiber carbo sugars potass
   <fct>     <fct> <fct>    <int>   <int> <int>  <int> <dbl> <dbl>  <int>  <int>
 1 Maypo     A     hot        100       4     1      0     0    16      3     95
 2 Total Ra… G     cold       140       3     1    190     4    15     14    230
 3 Mueslix … K     cold       160       3     2    150     3    17     13    160
 4 Cream of… N     hot        100       3     0     80     1    21      0     -1
 5 Fruit & … P     cold       120       3     2    160     5    12     10    200
 6 Great Gr… P     cold       120       3     3     75     3    13      4    100
 7 Post Nat… P     cold       120       3     1    200     6    11     14    260
 8 100% Nat… Q     cold       120       3     5     15     2     8      8    135
 9 Cap'n'Cr… Q     cold       120       1     2    220     0    12     12     35
10 Honey Gr… Q     cold       120       1     2    220     1    12     11     45
11 Muesli R… R     cold       150       4     3     95     3    16     11    170
12 Muesli R… R     cold       150       4     3    150     3    16     11    170
# ℹ 5 more variables: vitamins <int>, shelf <int>, weight <dbl>, cups <dbl>,
#   rating <dbl>

Multiple Variables in `slice()`

cereal |> 
  arrange(calories, sugars) |> 
  slice(1:3)

                       name manuf type calories protein fat sodium fiber carbo
1 All-Bran with Extra Fiber     K cold       50       4   0    140    14     8
2               Puffed Rice     Q cold       50       1   0      0     0    13
3              Puffed Wheat     Q cold       50       2   0      0     1    10
  sugars potass vitamins shelf weight cups   rating
1      0    330       25     3    1.0  0.5 93.70491
2      0     15        0     3    0.5  1.0 60.75611
3      0     50        0     3    0.5  1.0 63.00565

Piping into `ggplot()`

cereal |> 
  mutate(manuf = case_when(manuf == "A" ~ "American Home Food Products", 
                           manuf == "G" ~ "General Mills", 
                           manuf == "K" ~ "Kelloggs", 
                           manuf == "N" ~ "Nabisco", 
                           manuf == "P" ~ "Post", 
                           manuf == "Q" ~ "Quaker Oats", 
                           manuf == "R" ~ "Ralston Purina"
                           )
  ) |> 
  filter(type == "cold") |> 
  mutate(cal_per_cup = calories / cups) |> 
  group_by(manuf) |> 
  summarise(mean_cal_per_cup = mean(cal_per_cup)) |> 
  ggplot(aes(x = manuf, 
             y = mean_cal_per_cup, 
             shape = manuf)) +
  geom_point(show.legend = FALSE,
             size = 3) +
  labs(x = "Manufacturer",
       subtitle = "Calories per cup (mean)") +
  theme_bw() +
  theme(axis.title.y = element_blank(),
        axis.title.x  = element_text(size = 32),
        plot.subtitle = element_text(size = 32),
        axis.text = element_text(size = 28)
        )

Piping into `ggplot()`

Implication of Data Ethics

Data Science Oath

I will not be ashamed to say, “I know not,” nor will I fail to call in my colleagues when the skills of another are needed for solving a problem.

I will respect the privacy of my data subjects, for their data are not disclosed to me that the world may know, so I will tread with care in matters of privacy and security.

I will remember that my data are not just numbers without meaning or context, but represent real people and situations, and that my work may lead to unintended societal consequences, such as inequality, poverty, and disparities due to algorithmic bias.

Note

ASA Ethical Guidelines

The American Statistical Association’s Ethical Guidelines for Statistical Practice are intended to help statistics practitioners make decisions ethically. Additionally, the ethical guidelines aim to promote accountability by informing those who rely on statistical analysis of the standards they should expect.

Visit Ethical Guidelines for Statistical Practice and discuss one of the guidelines with your partner.

What surprises you? What did you learn?

What scenario might this come into play?

Institutional Review Board

IRB reviews help to ensure that research participants are protected from research-related risks and treated ethically, a necessary prerequisite for maintaining the public’s trust in the research enterprise and allowing science to advance for the common good.

Note

Watch a video about IRB to learn more.

Weekly Lab + Challenge

To do…

Lab 3: Hip Hop Lyrics
- Due Friday, 1/27 at 11:59pm
Challenge 3: Published Comparisons & Data Ethics
- Due Saturday, 1/28 at 11:59pm
Read Chapter 4: Data Joins and Transformations
- Concept Check 4.1 + 4.2 due Monday (1/30) at 8:00am

Data Cleaning & Manipulation

Monday, April 17

Example Data set – Cereal

Data Wrangling with dplyr

dplyr

dplyr verbs

The Pipe Operator

The Pipe Operator

The Pipe Operator

The Pipe Operator

Data Comes First!

filter()

filter()

filter()

filter(): Handy Helpers!

filter(): |

filter(): %in%

How do we “filter” in base R?

arrange()

arrange()

arrange()

arrange(): Descending Order

arrange(): Related Functions!

slice_max()

How do we “arrange” in base R?

select()

select()

select()

select(): Reordering

select(): Handy Helpers!

rename()

How do we “select” in base R?

mutate()

mutate()

mutate(): Handy Helpers!

How do we “mutate” in base R?

group_by()

group_by()

ungroup()

summarize()

summarize()

summarize(): Handy Helpers!

group_by() + summarize()!

group_by() + mutate()!

Glue it all together!

Save your changes!

Code Formatting

PA 3: Identify the Mystery College

To do…

Wednesday, April 19

Extending dplyr verbs

Example Data set – Cereal

Summarize or mutate multiple columns with across()

Discritize with if_else()

Re-leveling with case_when()

group_by() + slice()

Multiple Variables in slice()

Piping into ggplot()

Piping into ggplot()

Implication of Data Ethics

Data Science Oath

ASA Ethical Guidelines

Institutional Review Board

Weekly Lab + Challenge

To do…

Data Wrangling with `dplyr`

`dplyr`

`dplyr` verbs

`filter()`

`filter()`

`filter()`

`filter()`: Handy Helpers!

`filter()`: `|`

`filter()`: `%in%`

How do we “filter” in base `R`?

`arrange()`

`arrange()`

`arrange()`

`arrange()`: Descending Order

`arrange()`: Related Functions!

`slice_max()`

How do we “arrange” in base `R`?

`select()`

`select()`

`select()`

`select()`: Reordering

`select()`: Handy Helpers!

`rename()`

How do we “select” in base `R`?

`mutate()`

`mutate()`

`mutate()`: Handy Helpers!

How do we “mutate” in base `R`?

`group_by()`

`group_by()`

`ungroup()`

`summarize()`

`summarize()`

`summarize()`: Handy Helpers!

`group_by() + summarize()`!

`group_by() + mutate()`!

Extending `dplyr` verbs

Summarize or mutate multiple columns with `across()`

Discritize with `if_else()`

Re-leveling with `case_when()`

`group_by()` + `slice()`

Multiple Variables in `slice()`

Piping into `ggplot()`

Piping into `ggplot()`